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Lecture Comments (20)

0 answers

Post by Chris DesRochers on June 22, 2015

Couldn't it be said that in extra example 3 question 3 "a plane containing lines (script) l and (script)n would be either the plane names by the noncolinear points ABE and/or perhaps DBA, or even ADE? If not, why isn't this an acceptable answer/or conclusion to the question given the constraints of the problem?

Thank you,

Chris

0 answers

Post by Noah Romero on June 7, 2014

Thanks

1 answer

Last reply by: Manuela Campos
Wed Apr 30, 2014 11:15 AM

Post by Manoj Devashish on March 25, 2014

In the third drawing and labeling example,I don't get how a line can intersect with a plane.

1 answer

Last reply by: Professor Pyo
Thu Jan 2, 2014 3:30 PM

Post by Delores Sapp on October 19, 2013

Will the points ( if there are 4) form a certain figure if they are coplanar? Can they be connected in some way so you can determine if they are coplanar?

0 answers

Post by Delores Sapp on October 19, 2013

How can you tell if 4 points are coplanar?

0 answers

Post by Shahram Ahmadi N. Emran on July 12, 2013

Thanks

1 answer

Last reply by: Professor Pyo
Wed May 29, 2013 10:06 PM

Post by Manfred Berger on May 27, 2013

Should the fact that there's a right facing arrow on the line in example 2 prompt me to call it line AB rather than BA?

0 answers

Post by Leili Reza on October 23, 2012

thanks,,,,,, best

0 answers

Post by Joseph Reich on June 15, 2012

In drawing and labeling example 3, you should mention that lines l and m do not intersect. It is unclear from the sketch.

0 answers

Post by Edmund Mercado on February 20, 2012

In the Drawing and Labeling slide, the upper edge of plane N needs to be dotted because it should be hidden behind the intersecting plane R

0 answers

Post by Corinne Lee on July 14, 2011

I LIKE IT.

1 answer

Last reply by: Mary Pyo
Fri Aug 19, 2011 11:35 PM

Post by Sayaka Carpenter on July 1, 2011

how can you have a point that is not in the plane, if a plane is continuous, and it continues for ever?

3 answers

Last reply by: Joseph Reich
Fri Jun 15, 2012 5:45 PM

Post by David Hettwer on January 12, 2011

For the 3rd problem ("a plane containing lines l and n"), you indicate there is no plane that contains lines l and n. Wouldn't plane ADB be an answer to that question? That plane is not drawn on the figure but it seems like it is a correct answer.

Related Articles:

Points, Lines and Planes

  • All geometric figures consist of points
  • A point is usually named by a capital letter
  • A line passes through two points. Lines consist of an infinite number of points. A line is often named by two points on the line or by a lowercase script letter.
  • A plane is a flat surface that extends indefinitely in all directions. Planes are modeled by four-sided figures. A plane can be named by a capital script letter or by three non-collinear points in the plane

Points, Lines and Planes

Which quandrant does each point belong to?
A(1, 4) B( − 7, 10) C(9, − 2) D( − 15, − 4)
  • Quandrant I ( + , + ), Quandrant II ( − , + ), Quandrant III ( − , − ), Quandrant IV ( + , − )
Point A belongs to Quandrant I, Point B belongs to Quandrant II, Point C belongs to Quandrant IV, Point D belongs to Quandrant III.
Write the coordinates for the points on the following coordinate plane
A(4, 5), B(3, 0), C( − 1, 2), D( − 4, − 3)
Graph each point on the coordinate plane
A(0, 0), B(1, 4), C( − 2, − 6), D( − 4, − 4)
Points A(0, 0), B( − 2, − 3) and C(4, 6) are colinear. Find out whether each of the following points is colinear with A,B, C or not.
D( − 4, − 6), E(0, 1), F( − 2, 3)
  • Graph points D, E and F on the same coordinate plane as A, B and C.
Point D is colinear with A, B and C; Points E and F are not colinear with A, B and C.
Line y = 3x + 1 passes through points (0, 1), (1, 4) and ( − 1, − 2), what quandrants does this line go through?
This line passes through Quandrants I, II and III.
Write 2 points in Quandrant I that lie on the line y = x − 2
  • Points in Quandrant I are ( + , + )
(3, 1) (6, 4)
Write 2 points in Quandrant IV that lie on line y = − 2x + 1
  • Points in Quandrant IV are ( + , − )
(1, − 1) (3, − 5)
Decide whether the line that passes through points A(1, 1) and B (2, 3) also passes through originate.
  • Graph points A, B and the line passes through them on a coordinate plane.
On the image, the line doesn't pass through the originate.
Graph a line that passes through A ( − 5, − 2) and B ( − 1, 3).
  • Graph a line that passes through A(1, 4) and B( - 2, - 4).

*These practice questions are only helpful when you work on them offline on a piece of paper and then use the solution steps function to check your answer.

Answer

Points, Lines and Planes

Lecture Slides are screen-captured images of important points in the lecture. Students can download and print out these lecture slide images to do practice problems as well as take notes while watching the lecture.

Transcription: Points, Lines and Planes

Welcome back to Educator.com.0000

This lesson is on points, lines, and planes; we are going to go over each of those.0002

First, let's start with points: all geometric figures consist of points.0010

That means that, whether we have a triangle, a square, a rectangle...we have a line...0017

no matter what we have, it is always going to consist of an infinite number of points.0023

A point is usually named by a capital letter, like this: this is point A.0030

(x,y), that point right there, the ordered pair, is labeled A; it is called point A; that is how it is named--point A--by capital letter.0037

Next, lines: a line passes through two points; so whenever you have two points, you can always draw a line through them.0051

So, a line has at least two points; lines consist of an infinite number of points.0061

With this line here, line n, I have two points labeled here, A and B; but a line consists of an infinite number of points.0070

So, every point on this line is one of the infinite numbers; so we have many, many, many points on this line, not just 2.0079

A line is often named by two points on the line, or by a lowercase script letter.0091

The way we label it, or the way we name it: this is an n in script; I can call this line n, or I can call it line AB (any two points).0096

Now, this line has arrows at each end; that means it is going continuously forever, infinitely continuous.0112

It never stops; since it is going in both directions, I can say that this is line AB, or line BA; this can also be BA.0126

And this is actually supposed to go like this, AB; or it could be BA, because it is going both ways.0140

Line AB...now, when we say line AB, then we don't draw a line above it, like this, because,0153

when we say "line," that takes care of it; we don't have to draw the line, because we are saying "line."0160

Line AB or line BA...this can also be line n in script, or AB with a line above it--a symbol.0167

Next, for planes: a plane is a flat surface that extends indefinitely in all directions.0180

Planes are modeled by four-sided figures; even though this plane is drawn like this, a four-sided figure,0187

it is actually going to go on forever in any direction.0196

If I draw a point here, then I can include that in the plane, because the plane is two-dimensional;0202

so the points could be either on the plane...or it might not be.0210

But they are modeled by four-sided figures; and make sure that it is flat.0218

A plane can be named by a capital script letter or by three non-collinear points in the plane.0225

So, this whole plane is called N; we can name this N, by a capital script letter, or by three non-collinear points in the plane.0230

Here are three non-collinear points (non-collinear, meaning that they do not form a straight line):0245

it could be plane N (the whole thing is titled N, so it could be plane N), or it could be plane ABC: plane N or plane ABC.0254

Now, it doesn't have to be ABC; it could be plane BCA; it could be plane CBA, CAB...either one is fine.0266

Now, drawing and labeling points, lines, and planes: the first one here: we have a line.0281

Now, I know that this is kind of hard to see, because there is so much on this slide; but just take a look at this right here.0290

It is just the first part; this line is line n; I don't have two points on this line labeled,0297

so I can't name this line by its points; I can't call it line S; it has to be line n; that would be the only name for it.0308

So, S, a capital letter--that is how points are labeled: S, or point S, is on n, or line n.0318

I could say that line n contains point S, or I can say that line n passes through S, or point S.0329

Even if it doesn't say plane N or point S, just by the way that the letter is written,0342

how you see the letter, you can determine if it is a point, a line, or a plane.0348

The next one: l and p intersect in R; how do we know what these are?0355

It is lowercase and script; that means that they are names of lines, so line l and line p intersect in R.0362

It is just a capital letter, not scripted, so it is just a point, R; so l and p intersect in R; they intersect at point R.0372

l and p both contain R, meaning that point R is part of line l, and R is part of line p.0381

R is the intersection of l and p; line l and line p--R is the intersection of the two lines.0391

The next one: l (here is l, line l) and T...now, this might be a little hard to see,0402

but when this line goes through the plane, this is where it is touching; so think of poking your pencil through your paper.0412

Right where you poke it through, if you leave your pencil through the paper, that point where your pencil is touching the paper--that would be point T.0429

I know it is kind of hard to see, but just think of it that way.0440

So, line l and T, that point, are in plane P--a capital script letter; that is the plane.0443

P contains point T and line l; line l is just going sideways, so if you just drew a line on the paper, then that would be line l.0453

Line m intersects P, the plane, at T; this line right here intersects the plane at that point--that is their intersection point.0465

T is the intersection of m with P; T is a point; point T is the intersection of line m with plane P.0482

Your pencil through your paper--the intersection of a plane with a line--will be a point, and that is point T.0495

The next one: this is a little bit harder to see; I know that it is kind of squished in there.0504

But here we have two planes: this is plane N, and this is plane R.0511

We have a line that is the intersection of R and N; so if you look at this line, this line is passing through plane R,0519

and it is also passing through plane N; and on that line are points A and B.0533

OK, line AB...the reason why this is labeled line AB is because there is no name for this line; so you just have to name it by any two points on the line.0544

So, AB is in plane N, and it is in plane R; this line is in both.0560

N and R, both planes, contain line AB; what does that mean?0575

If this line is part of both planes, that means that the line is the intersection of the two planes.0587

Think of when you have two planes intersecting; they are always going to intersect at a line.0592

It is not going to be a single point, like a line and a plane; two planes intersect at a line.0599

We will actually go over that later; N and R intersect in line AB.0605

The line AB is the intersection of N and R; there are different ways to say it.0614

Let's go over some examples: State whether each is best modeled by a point, a line, or a plane.0621

A knot in a rope: the knot...if I have a rope, and I have a knot, well, this knot is like a point.0627

This one is going to be a point.0637

The second one: a piece of cloth: cloth--a four-sided figure--that would be a plane.0642

Number 3: the corner of a desk: if I have a desk, the corner is going to be a point.0653

And a taut piece of thread; this thread is going to be a line.0664

The next example: List all of the possible names for each figure.0677

Line AB: this line can be line n; that is one name.0680

It can be like that, line AB or line BA; it can also be BA in symbols, like that, or BA this way.0694

The next one: Plane N: this is one way to name it.0716

I can also say plane ABC, plane ACB, plane BAC, plane BCA, CAB, and CBA.0721

There are all of the ways that I can label this plane.0746

Refer to the figure to name each.0757

A line passing through point A: there is point A; a line that is passing through is line l.0760

Two points collinear with point D (collinear, meaning that they line up--they form a line):0776

two points collinear with point D, so two points that are on the same line: points B and E.0785

A plane containing lines l and n: well, there isn't a plane that contains lines l and n,0800

because this line l is not part of plane R.0819

How do we know? because it is passing through, so it is like the pencil that you poke through your paper.0824

It is not on the plane; it is just passing through the plane.0832

So, a plane containing lines l and n is not here.0836

If I asked for two lines that plane R contains, I could say plane R contains lines n and...0842

the other one right here; there is no name for it, so I can say line FC.0866

I can write it like that, or I can say and line FC, like that.0876

OK, the next example: Draw and label a figure for each relationship.0881

The first one is point P on line AB.0890

It is a line...draw a line AB; there is AB, and point P is on the line, so we can draw it like that.0895

CD, the next one: line CD lies in plane R and contains point F.0910

So, I have a plane; line CD lies in plane R (this is plane R) and contains point F; the line contains point F.0918

Points A, B, and C are collinear, but points B, C, and D are non-collinear.0947

OK, that means I can just draw a line first, or I can just draw the points first, points A, B, and C.0953

They are collinear, but points B, C (there are B and C), and D are non-collinear; so I can just draw D somewhere not on the line.0968

OK, so A, B, and C are collinear, but B, C, and D are non-collinear.0979

OK, the next one: planes D and E intersect in n.0985

Now, this is a line, because it is a lowercase script letter.0990

So, here is one plane; here is another plane; let's label this plane D; this could be plane E.0994

And then, where they intersect, right here--that will be line n.1019

OK, that is it for this lesson; thank you for watching Educator.com.1029

I. Tools of Geometry
  Coordinate Plane 16:41
   Intro 0:00 
   The Coordinate System 0:12 
    Coordinate Plane: X-axis and Y-axis 0:15 
    Quadrants 1:02 
    Origin 2:00 
    Ordered Pair 2:17 
   Coordinate Plane 2:59 
    Example: Writing Coordinates 3:01 
   Coordinate Plane, cont. 4:15 
    Example: Graphing & Coordinate Plane 4:17 
    Collinear 5:58 
   Extra Example 1: Writing Coordinates & Quadrants 7:34 
   Extra Example 2: Quadrants 8:52 
   Extra Example 3: Graphing & Coordinate Plane 10:58 
   Extra Example 4: Collinear 12:50 
  Points, Lines and Planes 17:17
   Intro 0:00 
   Points 0:07 
    Definition and Example of Points 0:09 
   Lines 0:50 
    Definition and Example of Lines 0:51 
   Planes 2:59 
    Definition and Example of Planes 3:00 
   Drawing and Labeling 4:40 
    Example 1: Drawing and Labeling 4:41 
    Example 2: Drawing and Labeling 5:54 
    Example 3: Drawing and Labeling 6:41 
    Example 4: Drawing and Labeling 8:23 
   Extra Example 1: Points, Lines and Planes 10:19 
   Extra Example 2: Naming Figures 11:16 
   Extra Example 3: Points, Lines and Planes 12:35 
   Extra Example 4: Draw and Label 14:44 
  Measuring Segments 31:31
   Intro 0:00 
   Segments 0:06 
    Examples of Segments 0:08 
   Ruler Postulate 1:30 
    Ruler Postulate 1:31 
   Segment Addition Postulate 5:02 
    Example and Definition of Segment Addition Postulate 5:03 
   Segment Addition Postulate 8:01 
    Example 1: Segment Addition Postulate 8:04 
    Example 2: Segment Addition Postulate 11:15 
   Pythagorean Theorem 12:36 
    Definition of Pythagorean Theorem 12:37 
   Pythagorean Theorem, cont. 15:49 
    Example: Pythagorean Theorem 15:50 
   Distance Formula 16:48 
    Example and Definition of Distance Formula 16:49 
   Extra Example 1: Find Each Measure 20:32 
   Extra Example 2: Find the Missing Measure 22:11 
   Extra Example 3: Find the Distance Between the Two Points 25:36 
   Extra Example 4: Pythagorean Theorem 29:33 
  Midpoints and Segment Congruence 42:26
   Intro 0:00 
   Definition of Midpoint 0:07 
    Midpoint 0:10 
   Midpoint Formulas 1:30 
    Midpoint Formula: On a Number Line 1:45 
    Midpoint Formula: In a Coordinate Plane 2:50 
   Midpoint 4:40 
    Example: Midpoint on a Number Line 4:43 
   Midpoint 6:05 
    Example: Midpoint in a Coordinate Plane 6:06 
   Midpoint 8:28 
    Example 1 8:30 
    Example 2 13:01 
   Segment Bisector 15:14 
    Definition and Example of Segment Bisector 15:15 
   Proofs 17:27 
    Theorem 17:53 
    Proof 18:21 
   Midpoint Theorem 19:37 
    Example: Proof & Midpoint Theorem 19:38 
   Extra Example 1: Midpoint on a Number Line 23:44 
   Extra Example 2: Drawing Diagrams 26:25 
   Extra Example 3: Midpoint 29:14 
   Extra Example 4: Segment Bisector 33:21 
  Angles 42:34
   Intro 0:00 
   Angles 0:05 
    Angle 0:07 
    Ray 0:23 
    Opposite Rays 2:09 
   Angles 3:22 
    Example: Naming Angle 3:23 
   Angles 6:39 
    Interior, Exterior, Angle 6:40 
    Measure and Degrees 7:38 
   Protractor Postulate 8:37 
    Example: Protractor Postulate 8:38 
   Angle Addition Postulate 11:41 
    Example: Angle addition Postulate 11:42 
   Classifying Angles 14:10 
    Acute Angle 14:16 
    Right Angles 14:30 
    Obtuse Angle 14:41 
   Angle Bisector 15:02 
    Example: Angle Bisector 15:04 
   Angle Relationships 16:43 
    Adjacent Angles 16:47 
    Vertical Angles 17:49 
    Linear Pair 19:40 
   Angle Relationships 20:31 
    Right Angles 20:32 
    Supplementary Angles 21:15 
    Complementary Angles 21:33 
   Extra Example 1: Angles 24:08 
   Extra Example 2: Angles 29:06 
   Extra Example 3: Angles 32:05 
   Extra Example 4 Angles 35:44 
II. Reasoning & Proof
  Inductive Reasoning 19:00
   Intro 0:00 
   Inductive Reasoning 0:05 
    Conjecture 0:06 
    Inductive Reasoning 0:15 
   Examples 0:55 
    Example: Sequence 0:56 
    More Example: Sequence 2:00 
   Using Inductive Reasoning 2:50 
    Example: Conjecture 2:51 
    More Example: Conjecture 3:48 
   Counterexamples 4:56 
    Counterexample 4:58 
   Extra Example 1: Conjecture 6:59 
   Extra Example 2: Sequence and Pattern 10:20 
   Extra Example 3: Inductive Reasoning 12:46 
   Extra Example 4: Conjecture and Counterexample 15:17 
  Conditional Statements 42:47
   Intro 0:00 
   If Then Statements 0:05 
    If Then Statements 0:06 
   Other Forms 2:29 
    Example: Without Then 2:40 
    Example: Using When 3:03 
    Example: Hypothesis 3:24 
   Identify the Hypothesis and Conclusion 3:52 
    Example 1: Hypothesis and Conclusion 3:58 
    Example 2: Hypothesis and Conclusion 4:31 
    Example 3: Hypothesis and Conclusion 5:38 
   Write in If Then Form 6:16 
    Example 1: Write in If Then Form 6:23 
    Example 2: Write in If Then Form 6:57 
    Example 3: Write in If Then Form 7:39 
   Other Statements 8:40 
    Other Statements 8:41 
   Converse Statements 9:18 
    Converse Statements 9:20 
   Converses and Counterexamples 11:04 
    Converses and Counterexamples 11:05 
    Example 1: Converses and Counterexamples 12:02 
    Example 2: Converses and Counterexamples 15:10 
    Example 3: Converses and Counterexamples 17:08 
   Inverse Statement 19:58 
    Definition and Example 19:59 
   Inverse Statement 21:46 
    Example 1: Inverse and Counterexample 21:47 
    Example 2: Inverse and Counterexample 23:34 
   Contrapositive Statement 25:20 
    Definition and Example 25:21 
   Contrapositive Statement 26:58 
    Example: Contrapositive Statement 27:00 
   Summary 29:03 
    Summary of Lesson 29:04 
   Extra Example 1: Hypothesis and Conclusion 32:20 
   Extra Example 2: If-Then Form 33:23 
   Extra Example 3: Converse, Inverse, and Contrapositive 34:54 
   Extra Example 4: Converse, Inverse, and Contrapositive 37:56 
  Point, Line, and Plane Postulates 17:24
   Intro 0:00 
   What are Postulates? 0:09 
    Definition of Postulates 0:10 
   Postulates 1:22 
    Postulate 1: Two Points 1:23 
    Postulate 2: Three Points 2:02 
    Postulate 3: Line 2:45 
   Postulates, cont.. 3:08 
    Postulate 4: Plane 3:09 
    Postulate 5: Two Points in a Plane 3:53 
   Postulates, cont.. 4:46 
    Postulate 6: Two Lines Intersect 4:47 
    Postulate 7: Two Plane Intersect 5:28 
   Using the Postulates 6:34 
    Examples: True or False 6:35 
   Using the Postulates 10:18 
    Examples: True or False 10:19 
   Extra Example 1: Always, Sometimes, or Never 12:22 
   Extra Example 2: Always, Sometimes, or Never 13:15 
   Extra Example 3: Always, Sometimes, or Never 14:16 
   Extra Example 4: Always, Sometimes, or Never 15:03 
  Deductive Reasoning 36:03
   Intro 0:00 
   Deductive Reasoning 0:06 
    Definition of Deductive Reasoning 0:07 
   Inductive vs. Deductive 2:51 
    Inductive Reasoning 2:52 
    Deductive reasoning 3:19 
   Law of Detachment 3:47 
    Law of Detachment 3:48 
    Examples of Law of Detachment 4:31 
   Law of Syllogism 7:32 
    Law of Syllogism 7:33 
    Example 1: Making a Conclusion 9:02 
    Example 2: Making a Conclusion 12:54 
   Using Laws of Logic 14:12 
    Example 1: Determine the Logic 14:42 
    Example 2: Determine the Logic 17:02 
   Using Laws of Logic, cont. 18:47 
    Example 3: Determine the Logic 19:03 
    Example 4: Determine the Logic 20:56 
   Extra Example 1: Determine the Conclusion and Law 22:12 
   Extra Example 2: Determine the Conclusion and Law 25:39 
   Extra Example 3: Determine the Logic and Law 29:50 
   Extra Example 4: Determine the Logic and Law 31:27 
  Proofs in Algebra: Properties of Equality 44:31
   Intro 0:00 
   Properties of Equality 0:10 
    Addition Property of Equality 0:28 
    Subtraction Property of Equality 1:10 
    Multiplication Property of Equality 1:41 
    Division Property of Equality 1:55 
    Addition Property of Equality Using Angles 2:46 
   Properties of Equality, cont. 4:10 
    Reflexive Property of Equality 4:11 
    Symmetric Property of Equality 5:24 
    Transitive Property of Equality 6:10 
   Properties of Equality, cont. 7:04 
    Substitution Property of Equality 7:05 
    Distributive Property of Equality 8:34 
   Two Column Proof 9:40 
    Example: Two Column Proof 9:46 
   Proof Example 1 16:13 
   Proof Example 2 23:49 
   Proof Example 3 30:33 
   Extra Example 1: Name the Property of Equality 38:07 
   Extra Example 2: Name the Property of Equality 40:16 
   Extra Example 3: Name the Property of Equality 41:35 
   Extra Example 4: Name the Property of Equality 43:02 
  Proving Segment Relationship 41:02
   Intro 0:00 
   Good Proofs 0:12 
    Five Essential Parts 0:13 
   Proof Reasons 1:38 
    Undefined 1:40 
    Definitions 2:06 
    Postulates 2:42 
    Previously Proven Theorems 3:24 
   Congruence of Segments 4:10 
    Theorem: Congruence of Segments 4:12 
   Proof Example 10:16 
    Proof: Congruence of Segments 10:17 
   Setting Up Proofs 19:13 
    Example: Two Segments with Equal Measures 19:15 
   Setting Up Proofs 21:48 
    Example: Vertical Angles are Congruent 21:50 
   Setting Up Proofs 23:59 
    Example: Segment of a Triangle 24:00 
   Extra Example 1: Congruence of Segments 27:03 
   Extra Example 2: Setting Up Proofs 28:50 
   Extra Example 3: Setting Up Proofs 30:55 
   Extra Example 4: Two-Column Proof 33:11 
  Proving Angle Relationships 33:37
   Intro 0:00 
   Supplement Theorem 0:05 
    Supplementary Angles 0:06 
   Congruence of Angles 2:37 
    Proof: Congruence of Angles 2:38 
   Angle Theorems 6:54 
    Angle Theorem 1: Supplementary Angles 6:55 
    Angle Theorem 2: Complementary Angles 10:25 
   Angle Theorems 11:32 
    Angle Theorem 3: Right Angles 11:35 
    Angle Theorem 4: Vertical Angles 12:09 
    Angle Theorem 5: Perpendicular Lines 12:57 
   Using Angle Theorems 13:45 
    Example 1: Always, Sometimes, or Never 13:50 
    Example 2: Always, Sometimes, or Never 14:28 
    Example 3: Always, Sometimes, or Never 16:21 
   Extra Example 1: Always, Sometimes, or Never 16:53 
   Extra Example 2: Find the Measure of Each Angle 18:55 
   Extra Example 3: Find the Measure of Each Angle 25:03 
   Extra Example 4: Two-Column Proof 27:08 
III. Perpendicular & Parallel Lines
  Parallel Lines and Transversals 37:35
   Intro 0:00 
   Lines 0:06 
    Parallel Lines 0:09 
    Skew Lines 2:02 
    Transversal 3:42 
   Angles Formed by a Transversal 4:28 
    Interior Angles 5:53 
    Exterior Angles 6:09 
    Consecutive Interior Angles 7:04 
    Alternate Exterior Angles 9:47 
    Alternate Interior Angles 11:22 
    Corresponding Angles 12:27 
   Angles Formed by a Transversal 15:29 
    Relationship Between Angles 15:30 
   Extra Example 1: Intersecting, Parallel, or Skew 19:26 
   Extra Example 2: Draw a Diagram 21:37 
   Extra Example 3: Name the Figures 24:12 
   Extra Example 4: Angles Formed by a Transversal 28:38 
  Angles and Parallel Lines 41:53
   Intro 0:00 
   Corresponding Angles Postulate 0:05 
    Corresponding Angles Postulate 0:06 
   Alternate Interior Angles Theorem 3:05 
    Alternate Interior Angles Theorem 3:07 
   Consecutive Interior Angles Theorem 5:16 
    Consecutive Interior Angles Theorem 5:17 
   Alternate Exterior Angles Theorem 6:42 
    Alternate Exterior Angles Theorem 6:43 
   Parallel Lines Cut by a Transversal 7:18 
    Example: Parallel Lines Cut by a Transversal 7:19 
   Perpendicular Transversal Theorem 14:54 
    Perpendicular Transversal Theorem 14:55 
   Extra Example 1: State the Postulate or Theorem 16:37 
   Extra Example 2: Find the Measure of the Numbered Angle 18:53 
   Extra Example 3: Find the Measure of Each Angle 25:13 
   Extra Example 4: Find the Values of x, y, and z 36:26 
  Slope of Lines 44:06
   Intro 0:00 
   Definition of Slope 0:06 
    Slope Equation 0:13 
   Slope of a Line 3:45 
    Example: Find the Slope of a Line 3:47 
   Slope of a Line 8:38 
    More Example: Find the Slope of a Line 8:40 
   Slope Postulates 12:32 
    Proving Slope Postulates 12:33 
   Parallel or Perpendicular Lines 17:23 
    Example: Parallel or Perpendicular Lines 17:24 
   Using Slope Formula 20:02 
    Example: Using Slope Formula 20:03 
   Extra Example 1: Slope of a Line 25:10 
   Extra Example 2: Slope of a Line 26:31 
   Extra Example 3: Graph the Line 34:11 
   Extra Example 4: Using the Slope Formula 38:50 
  Proving Lines Parallel 25:55
   Intro 0:00 
   Postulates 0:06 
    Postulate 1: Parallel Lines 0:21 
    Postulate 2: Parallel Lines 2:16 
   Parallel Postulate 3:28 
    Definition and Example of Parallel Postulate 3:29 
   Theorems 4:29 
    Theorem 1: Parallel Lines 4:40 
    Theorem 2: Parallel Lines 5:37 
   Theorems, cont. 6:10 
    Theorem 3: Parallel Lines 6:11 
   Extra Example 1: Determine Parallel Lines 6:56 
   Extra Example 2: Find the Value of x 11:42 
   Extra Example 3: Opposite Sides are Parallel 14:48 
   Extra Example 4: Proving Parallel Lines 20:42 
  Parallels and Distance 19:48
   Intro 0:00 
   Distance Between a Points and Line 0:07 
    Definition and Example 0:08 
   Distance Between Parallel Lines 1:51 
    Definition and Example 1:52 
   Extra Example 1: Drawing a Segment to Represent Distance 3:02 
   Extra Example 2: Drawing a Segment to Represent Distance 4:27 
   Extra Example 3: Graph, Plot, and Construct a Perpendicular Segment 5:13 
   Extra Example 4: Distance Between Two Parallel Lines 15:37 
IV. Congruent Triangles
  Classifying Triangles 28:43
   Intro 0:00 
   Triangles 0:09 
    Triangle: A Three-Sided Polygon 0:10 
    Sides 1:00 
    Vertices 1:22 
    Angles 1:56 
   Classifying Triangles by Angles 2:59 
    Acute Triangle 3:19 
    Obtuse Triangle 4:08 
    Right Triangle 4:44 
   Equiangular Triangle 5:38 
    Definition and Example of an Equiangular Triangle 5:39 
   Classifying Triangles by Sides 6:57 
    Scalene Triangle 7:17 
    Isosceles Triangle 7:57 
    Equilateral Triangle 8:12 
   Isosceles Triangle 8:58 
    Labeling Isosceles Triangle 9:00 
    Labeling Right Triangle 10:44 
   Isosceles Triangle 11:10 
    Example: Find x, AB, BC, and AC 11:11 
   Extra Example 1: Classify Each Triangle 13:45 
   Extra Example 2: Always, Sometimes, or Never 16:28 
   Extra Example 3: Find All the Sides of the Isosceles Triangle 20:29 
   Extra Example 4: Distance Formula and Triangle 22:29 
  Measuring Angles in Triangles 44:43
   Intro 0:00 
   Angle Sum Theorem 0:09 
    Angle Sum Theorem for Triangle 0:11 
   Using Angle Sum Theorem 4:06 
    Find the Measure of the Missing Angle 4:07 
   Third Angle Theorem 4:58 
    Example: Third Angle Theorem 4:59 
   Exterior Angle Theorem 7:58 
    Example: Exterior Angle Theorem 8:00 
   Flow Proof of Exterior Angle Theorem 15:14 
    Flow Proof of Exterior Angle Theorem 15:17 
   Triangle Corollaries 27:21 
    Triangle Corollary 1 27:50 
    Triangle Corollary 2 30:42 
   Extra Example 1: Find the Value of x 32:55 
   Extra Example 2: Find the Value of x 34:20 
   Extra Example 3: Find the Measure of the Angle 35:38 
   Extra Example 4: Find the Measure of Each Numbered Angle 39:00 
  Exploring Congruent Triangles 26:46
   Intro 0:00 
   Congruent Triangles 0:15 
    Example of Congruent Triangles 0:17 
   Corresponding Parts 3:39 
    Corresponding Angles and Sides of Triangles 3:40 
   Definition of Congruent Triangles 11:24 
    Definition of Congruent Triangles 11:25 
   Triangle Congruence 16:37 
    Congruence of Triangles 16:38 
   Extra Example 1: Congruence Statement 18:24 
   Extra Example 2: Congruence Statement 21:26 
   Extra Example 3: Draw and Label the Figure 23:09 
   Extra Example 4: Drawing Triangles 24:04 
  Proving Triangles Congruent 47:51
   Intro 0:00 
   SSS Postulate 0:18 
    Side-Side-Side Postulate 0:27 
   SAS Postulate 2:26 
    Side-Angle-Side Postulate 2:29 
   SAS Postulate 3:57 
    Proof Example 3:58 
   ASA Postulate 11:47 
    Angle-Side-Angle Postulate 11:53 
   AAS Theorem 14:13 
    Angle-Angle-Side Theorem 14:14 
   Methods Overview 16:16 
    Methods Overview 16:17 
    SSS 16:33 
    SAS 17:06 
    ASA 17:50 
    AAS 18:17 
    CPCTC 19:14 
   Extra Example 1:Proving Triangles are Congruent 21:29 
   Extra Example 2: Proof 25:40 
   Extra Example 3: Proof 30:41 
   Extra Example 4: Proof 38:41 
  Isosceles and Equilateral Triangles 27:53
   Intro 0:00 
   Isosceles Triangle Theorem 0:07 
    Isosceles Triangle Theorem 0:09 
   Isosceles Triangle Theorem 2:26 
    Example: Using the Isosceles Triangle Theorem 2:27 
   Isosceles Triangle Theorem Converse 3:29 
    Isosceles Triangle Theorem Converse 3:30 
   Equilateral Triangle Theorem Corollaries 4:30 
    Equilateral Triangle Theorem Corollary 1 4:59 
    Equilateral Triangle Theorem Corollary 2 5:55 
   Extra Example 1: Find the Value of x 7:08 
   Extra Example 2: Find the Value of x 10:04 
   Extra Example 3: Proof 14:04 
   Extra Example 4: Proof 22:41 
V. Triangle Inequalities
  Special Segments in Triangles 43:44
   Intro 0:00 
   Perpendicular Bisector 0:06 
    Perpendicular Bisector 0:07 
   Perpendicular Bisector 4:07 
    Perpendicular Bisector Theorems 4:08 
   Median 6:30 
    Definition of Median 6:31 
   Median 9:41 
    Example: Median 9:42 
   Altitude 12:22 
    Definition of Altitude 12:23 
   Angle Bisector 14:33 
    Definition of Angle Bisector 14:34 
   Angle Bisector 16:41 
    Angle Bisector Theorems 16:42 
   Special Segments Overview 18:57 
    Perpendicular Bisector 19:04 
    Median 19:32 
    Altitude 19:49 
    Angle Bisector 20:02 
    Examples: Special Segments 20:18 
   Extra Example 1: Draw and Label 22:36 
   Extra Example 2: Draw the Altitudes for Each Triangle 24:37 
   Extra Example 3: Perpendicular Bisector 27:57 
   Extra Example 4: Draw, Label, and Write Proof 34:33 
  Right Triangles 26:34
   Intro 0:00 
   LL Theorem 0:21 
    Leg-Leg Theorem 0:25 
   HA Theorem 2:23 
    Hypotenuse-Angle Theorem 2:24 
   LA Theorem 4:49 
    Leg-Angle Theorem 4:50 
   LA Theorem 6:18 
    Example: Find x and y 6:19 
   HL Postulate 8:22 
    Hypotenuse-Leg Postulate 8:23 
   Extra Example 1: LA Theorem & HL Postulate 10:57 
   Extra Example 2: Find x So That Each Pair of Triangles is Congruent 14:15 
   Extra Example 3: Two-column Proof 17:02 
   Extra Example 4: Two-column Proof 21:01 
  Indirect Proofs and Inequalities 33:30
   Intro 0:00 
   Writing an Indirect Proof 0:09 
    Step 1 0:49 
    Step 2 2:32 
    Step 3 3:00 
   Indirect Proof 4:30 
    Example: 2 + 6 = 8 5:00 
    Example: The Suspect is Guilty 5:40 
    Example: Measure of Angle A < Measure of Angle B 6:06 
   Definition of Inequality 7:47 
    Definition of Inequality & Example 7:48 
   Properties of Inequality 9:55 
    Comparison Property 9:58 
    Transitive Property 10:33 
    Addition and Subtraction Properties 12:01 
    Multiplication and Division Properties 13:07 
   Exterior Angle Inequality Theorem 14:12 
    Example: Exterior Angle Inequality Theorem 14:13 
   Extra Example 1: Draw a Diagram for the Statement 18:32 
   Extra Example 2: Name the Property for Each Statement 19:56 
   Extra Example 3: State the Assumption 21:22 
   Extra Example 4: Write an Indirect Proof 25:39 
  Inequalities for Sides and Angles of a Triangle 17:26
   Intro 0:00 
   Side to Angles 0:10 
    If One Side of a Triangle is Longer Than Another Side 0:11 
   Converse: Angles to Sides 1:57 
    If One Angle of a Triangle Has a Greater Measure Than Another Angle 1:58 
   Extra Example 1: Name the Angles in the Triangle From Least to Greatest 2:38 
   Extra Example 2: Find the Longest and Shortest Segment in the Triangle 3:47 
   Extra Example 3: Angles and Sides of a Triangle 4:51 
   Extra Example 4: Two-column Proof 9:08 
  Triangle Inequality 28:11
   Intro 0:00 
   Triangle Inequality Theorem 0:05 
    Triangle Inequality Theorem 0:06 
   Triangle Inequality Theorem 4:22 
    Example 1: Triangle Inequality Theorem 4:23 
    Example 2: Triangle Inequality Theorem 9:40 
   Extra Example 1: Determine if the Three Numbers can Represent the Sides of a Triangle 12:00 
   Extra Example 2: Finding the Third Side of a Triangle 13:34 
   Extra Example 3: Always True, Sometimes True, or Never True 18:18 
   Extra Example 4: Triangle and Vertices 22:36 
  Inequalities Involving Two Triangles 29:36
   Intro 0:00 
   SAS Inequality Theorem 0:06 
    SAS Inequality Theorem & Example 0:25 
   SSS Inequality Theorem 4:33 
    SSS Inequality Theorem & Example 4:34 
   Extra Example 1: Write an Inequality Comparing the Segments 6:08 
   Extra Example 2: Determine if the Statement is True 9:52 
   Extra Example 3: Write an Inequality for x 14:20 
   Extra Example 4: Two-column Proof 17:44 
VI. Quadrilaterals
  Parallelograms 29:11
   Intro 0:00 
   Quadrilaterals 0:06 
    Four-sided Polygons 0:08 
    Non Examples of Quadrilaterals 0:47 
   Parallelograms 1:35 
    Parallelograms 1:36 
   Properties of Parallelograms 4:28 
    Opposite Sides of a Parallelogram are Congruent 4:29 
    Opposite Angles of a Parallelogram are Congruent 5:49 
   Angles and Diagonals 6:24 
    Consecutive Angles in a Parallelogram are Supplementary 6:25 
    The Diagonals of a Parallelogram Bisect Each Other 8:42 
   Extra Example 1: Complete Each Statement About the Parallelogram 10:26 
   Extra Example 2: Find the Values of x, y, and z of the Parallelogram 13:21 
   Extra Example 3: Find the Distance of Each Side to Verify the Parallelogram 16:35 
   Extra Example 4: Slope of Parallelogram 23:15 
  Proving Parallelograms 42:43
   Intro 0:00 
   Parallelogram Theorems 0:09 
    Theorem 1 0:20 
    Theorem 2 1:50 
   Parallelogram Theorems, Cont. 3:10 
    Theorem 3 3:11 
    Theorem 4 4:15 
   Proving Parallelogram 6:21 
    Example: Determine if Quadrilateral ABCD is a Parallelogram 6:22 
   Summary 14:01 
    Both Pairs of Opposite Sides are Parallel 14:14 
    Both Pairs of Opposite Sides are Congruent 15:09 
    Both Pairs of Opposite Angles are Congruent 15:24 
    Diagonals Bisect Each Other 15:44 
    A Pair of Opposite Sides is Both Parallel and Congruent 16:13 
   Extra Example 1: Determine if Each Quadrilateral is a Parallelogram 16:54 
   Extra Example 2: Find the Value of x and y 20:23 
   Extra Example 3: Determine if the Quadrilateral ABCD is a Parallelogram 24:05 
   Extra Example 4: Two-column Proof 30:28 
  Rectangles 29:47
   Intro 0:00 
   Rectangles 0:03 
    Definition of Rectangles 0:04 
   Diagonals of Rectangles 2:52 
    Rectangles: Diagonals Property 1 2:53 
    Rectangles: Diagonals Property 2 3:30 
   Proving a Rectangle 4:40 
    Example: Determine Whether Parallelogram ABCD is a Rectangle 4:41 
   Rectangles Summary 9:22 
    Opposite Sides are Congruent and Parallel 9:40 
    Opposite Angles are Congruent 9:51 
    Consecutive Angles are Supplementary 9:58 
    Diagonals are Congruent and Bisect Each Other 10:05 
    All Four Angles are Right Angles 10:40 
   Extra Example 1: Find the Value of x 11:03 
   Extra Example 2: Name All Congruent Sides and Angles 13:52 
   Extra Example 3: Always, Sometimes, or Never True 19:39 
   Extra Example 4: Determine if ABCD is a Rectangle 26:45 
  Squares and Rhombi 39:14
   Intro 0:00 
   Rhombus 0:09 
    Definition of a Rhombus 0:10 
   Diagonals of a Rhombus 2:03 
    Rhombus: Diagonals Property 1 2:21 
    Rhombus: Diagonals Property 2 3:49 
    Rhombus: Diagonals Property 3 4:36 
   Rhombus 6:17 
    Example: Use the Rhombus to Find the Missing Value 6:18 
   Square 8:17 
    Definition of a Square 8:20 
   Summary Chart 11:06 
    Parallelogram 11:07 
    Rectangle 12:56 
    Rhombus 13:54 
    Square 14:44 
   Extra Example 1: Diagonal Property 15:44 
   Extra Example 2: Use Rhombus ABCD to Find the Missing Value 19:39 
   Extra Example 3: Always, Sometimes, or Never True 23:06 
   Extra Example 4: Determine the Quadrilateral 28:02 
  Trapezoids and Kites 30:48
   Intro 0:00 
   Trapezoid 0:10 
    Definition of Trapezoid 0:12 
   Isosceles Trapezoid 2:57 
    Base Angles of an Isosceles Trapezoid 2:58 
    Diagonals of an Isosceles Trapezoid 4:05 
   Median of a Trapezoid 4:26 
    Median of a Trapezoid 4:27 
   Median of a Trapezoid 6:41 
    Median Formula 7:00 
   Kite 8:28 
    Definition of a Kite 8:29 
   Quadrilaterals Summary 11:19 
    A Quadrilateral with Two Pairs of Adjacent Congruent Sides 11:20 
   Extra Example 1: Isosceles Trapezoid 14:50 
   Extra Example 2: Median of Trapezoid 18:28 
   Extra Example 3: Always, Sometimes, or Never 24:13 
   Extra Example 4: Determine if the Figure is a Trapezoid 26:49 
VII. Proportions and Similarity
  Using Proportions and Ratios 20:10
   Intro 0:00 
   Ratio 0:05 
    Definition and Examples of Writing Ratio 0:06 
   Proportion 2:05 
    Definition of Proportion 2:06 
    Examples of Proportion 2:29 
   Using Ratio 5:53 
    Example: Ratio 5:54 
   Extra Example 1: Find Three Ratios Equivalent to 2/5 9:28 
   Extra Example 2: Proportion and Cross Products 10:32 
   Extra Example 3: Express Each Ratio as a Fraction 13:18 
   Extra Example 4: Fin the Measure of a 3:4:5 Triangle 17:26 
  Similar Polygons 27:53
   Intro 0:00 
   Similar Polygons 0:05 
    Definition of Similar Polygons 0:06 
    Example of Similar Polygons 2:32 
   Scale Factor 4:26 
    Scale Factor: Definition and Example 4:27 
   Extra Example 1: Determine if Each Pair of Figures is Similar 7:03 
   Extra Example 2: Find the Values of x and y 11:33 
   Extra Example 3: Similar Triangles 19:57 
   Extra Example 4: Draw Two Similar Figures 23:36 
  Similar Triangles 34:10
   Intro 0:00 
   AA Similarity 0:10 
    Definition of AA Similarity 0:20 
    Example of AA Similarity 2:32 
   SSS Similarity 4:46 
    Definition of SSS Similarity 4:47 
    Example of SSS Similarity 6:00 
   SAS Similarity 8:04 
    Definition of SAS Similarity 8:05 
    Example of SAS Similarity 9:12 
   Extra Example 1: Determine Whether Each Pair of Triangles is Similar 10:59 
   Extra Example 2: Determine Which Triangles are Similar 16:08 
   Extra Example 3: Determine if the Statement is True or False 23:11 
   Extra Example 4: Write Two-Column Proof 26:25 
  Parallel Lines and Proportional Parts 24:07
   Intro 0:00 
   Triangle Proportionality 0:07 
    Definition of Triangle Proportionality 0:08 
    Example of Triangle Proportionality 0:51 
   Triangle Proportionality Converse 2:19 
    Triangle Proportionality Converse 2:20 
   Triangle Mid-segment 3:42 
    Triangle Mid-segment: Definition and Example 3:43 
   Parallel Lines and Transversal 6:51 
    Parallel Lines and Transversal 6:52 
   Extra Example 1: Complete Each Statement 8:59 
   Extra Example 2: Determine if the Statement is True or False 12:28 
   Extra Example 3: Find the Value of x and y 15:35 
   Extra Example 4: Find Midpoints of a Triangle 20:43 
  Parts of Similar Triangles 27:06
   Intro 0:00 
   Proportional Perimeters 0:09 
    Proportional Perimeters: Definition and Example 0:10 
   Similar Altitudes 2:23 
    Similar Altitudes: Definition and Example 2:24 
   Similar Angle Bisectors 4:50 
    Similar Angle Bisectors: Definition and Example 4:51 
   Similar Medians 6:05 
    Similar Medians: Definition and Example 6:06 
   Angle Bisector Theorem 7:33 
    Angle Bisector Theorem 7:34 
   Extra Example 1: Parts of Similar Triangles 10:52 
   Extra Example 2: Parts of Similar Triangles 14:57 
   Extra Example 3: Parts of Similar Triangles 19:27 
   Extra Example 4: Find the Perimeter of Triangle ABC 23:14 
VIII. Applying Right Triangles & Trigonometry
  Pythagorean Theorem 21:14
   Intro 0:00 
   Pythagorean Theorem 0:05 
    Pythagorean Theorem & Example 0:06 
   Pythagorean Converse 1:20 
    Pythagorean Converse & Example 1:21 
   Pythagorean Triple 2:42 
    Pythagorean Triple 2:43 
   Extra Example 1: Find the Missing Side 4:59 
   Extra Example 2: Determine Right Triangle 7:40 
   Extra Example 3: Determine Pythagorean Triple 11:30 
   Extra Example 4: Vertices and Right Triangle 14:29 
  Geometric Mean 40:59
   Intro 0:00 
   Geometric Mean 0:04 
    Geometric Mean & Example 0:05 
   Similar Triangles 4:32 
    Similar Triangles 4:33 
   Geometric Mean-Altitude 11:10 
    Geometric Mean-Altitude & Example 11:11 
   Geometric Mean-Leg 14:47 
    Geometric Mean-Leg & Example 14:18 
   Extra Example 1: Geometric Mean Between Each Pair of Numbers 20:10 
   Extra Example 2: Similar Triangles 23:46 
   Extra Example 3: Geometric Mean of Triangles 28:30 
   Extra Example 4: Geometric Mean of Triangles 36:58 
  Special Right Triangles 37:57
   Intro 0:00 
   45-45-90 Triangles 0:06 
    Definition of 45-45-90 Triangles 0:25 
   45-45-90 Triangles 5:51 
    Example: Find n 5:52 
   30-60-90 Triangles 8:59 
    Definition of 30-60-90 Triangles 9:00 
   30-60-90 Triangles 12:25 
    Example: Find n 12:26 
   Extra Example 1: Special Right Triangles 15:08 
   Extra Example 2: Special Right Triangles 18:22 
   Extra Example 3: Word Problems & Special Triangles 27:40 
   Extra Example 4: Hexagon & Special Triangles 33:51 
  Ratios in Right Triangles 40:37
   Intro 0:00 
   Trigonometric Ratios 0:08 
    Definition of Trigonometry 0:13 
    Sine (sin), Cosine (cos), & Tangent (tan) 0:50 
   Trigonometric Ratios 3:04 
    Trig Functions 3:05 
    Inverse Trig Functions 5:02 
   SOHCAHTOA 8:16 
    sin x 9:07 
    cos x 10:00 
    tan x 10:32 
    Example: SOHCAHTOA & Triangle 12:10 
   Extra Example 1: Find the Value of Each Ratio or Angle Measure 14:36 
   Extra Example 2: Find Sin, Cos, and Tan 18:51 
   Extra Example 3: Find the Value of x Using SOHCAHTOA 22:55 
   Extra Example 4: Trigonometric Ratios in Right Triangles 32:13 
  Angles of Elevation and Depression 21:04
   Intro 0:00 
   Angle of Elevation 0:10 
    Definition of Angle of Elevation & Example 0:11 
   Angle of Depression 1:19 
    Definition of Angle of Depression & Example 1:20 
   Extra Example 1: Name the Angle of Elevation and Depression 2:22 
   Extra Example 2: Word Problem & Angle of Depression 4:41 
   Extra Example 3: Word Problem & Angle of Elevation 14:02 
   Extra Example 4: Find the Missing Measure 18:10 
  Law of Sines 35:25
   Intro 0:00 
   Law of Sines 0:20 
    Law of Sines 0:21 
   Law of Sines 3:34 
    Example: Find b 3:35 
   Solving the Triangle 9:19 
    Example: Using the Law of Sines to Solve Triangle 9:20 
   Extra Example 1: Law of Sines and Triangle 17:43 
   Extra Example 2: Law of Sines and Triangle 20:06 
   Extra Example 3: Law of Sines and Triangle 23:54 
   Extra Example 4: Law of Sines and Triangle 28:59 
  Law of Cosines 52:43
   Intro 0:00 
   Law of Cosines 0:35 
    Law of Cosines 0:36 
   Law of Cosines 6:22 
    Use the Law of Cosines When Both are True 6:23 
   Law of Cosines 8:35 
    Example: Law of Cosines 8:36 
   Extra Example 1: Law of Sines or Law of Cosines? 13:35 
   Extra Example 2: Use the Law of Cosines to Find the Missing Measure 17:02 
   Extra Example 3: Solve the Triangle 30:49 
   Extra Example 4: Find the Measure of Each Diagonal of the Parallelogram 41:39 
IX. Circles
  Segments in a Circle 22:43
   Intro 0:00 
   Segments in a Circle 0:10 
    Circle 0:11 
    Chord 0:59 
    Diameter 1:32 
    Radius 2:07 
    Secant 2:17 
    Tangent 3:10 
   Circumference 3:56 
    Introduction to Circumference 3:57 
    Example: Find the Circumference of the Circle 5:09 
   Circumference 6:40 
    Example: Find the Circumference of the Circle 6:41 
   Extra Example 1: Use the Circle to Answer the Following 9:10 
   Extra Example 2: Find the Missing Measure 12:53 
   Extra Example 3: Given the Circumference, Find the Perimeter of the Triangle 15:51 
   Extra Example 4: Find the Circumference of Each Circle 19:24 
  Angles and Arc 35:24
   Intro 0:00 
   Central Angle 0:06 
    Definition of Central Angle 0:07 
   Sum of Central Angles 1:17 
    Sum of Central Angles 1:18 
   Arcs 2:27 
    Minor Arc 2:30 
    Major Arc 3:47 
   Arc Measure 5:24 
    Measure of Minor Arc 5:24 
    Measure of Major Arc 6:53 
    Measure of a Semicircle 7:11 
   Arc Addition Postulate 8:25 
    Arc Addition Postulate 8:26 
   Arc Length 9:43 
    Arc Length and Example 9:44 
   Concentric Circles 16:05 
    Concentric Circles 16:06 
   Congruent Circles and Arcs 17:50 
    Congruent Circles 17:51 
    Congruent Arcs 18:47 
   Extra Example 1: Minor Arc, Major Arc, and Semicircle 20:14 
   Extra Example 2: Measure and Length of Arc 22:52 
   Extra Example 3: Congruent Arcs 25:48 
   Extra Example 4: Angles and Arcs 30:33 
  Arcs and Chords 21:51
   Intro 0:00 
   Arcs and Chords 0:07 
    Arc of the Chord 0:08 
    Theorem 1: Congruent Minor Arcs 1:01 
   Inscribed Polygon 2:10 
    Inscribed Polygon 2:11 
   Arcs and Chords 3:18 
    Theorem 2: When a Diameter is Perpendicular to a Chord 3:19 
   Arcs and Chords 5:05 
    Theorem 3: Congruent Chords 5:06 
   Extra Example 1: Congruent Arcs 10:35 
   Extra Example 2: Length of Arc 13:50 
   Extra Example 3: Arcs and Chords 17:09 
   Extra Example 4: Arcs and Chords 19:45 
  Inscribed Angles 27:53
   Intro 0:00 
   Inscribed Angles 0:07 
    Definition of Inscribed Angles 0:08 
   Inscribed Angles 0:58 
    Inscribed Angle Theorem 1 0:59 
   Inscribed Angles 3:29 
    Inscribed Angle Theorem 2 3:30 
   Inscribed Angles 4:38 
    Inscribed Angle Theorem 3 4:39 
   Inscribed Quadrilateral 5:50 
    Inscribed Quadrilateral 5:51 
   Extra Example 1: Central Angle, Inscribed Angle, and Intercepted Arc 7:02 
   Extra Example 2: Inscribed Angles 9:24 
   Extra Example 3: Inscribed Angles 14:00 
   Extra Example 4: Complete the Proof 17:58 
  Tangents 26:16
   Intro 0:00 
   Tangent Theorems 0:04 
    Tangent Theorem 1 0:05 
    Tangent Theorem 1 Converse 0:55 
   Common Tangents 1:34 
    Common External Tangent 2:12 
    Common Internal Tangent 2:30 
   Tangent Segments 3:08 
    Tangent Segments 3:09 
   Circumscribed Polygons 4:11 
    Circumscribed Polygons 4:12 
   Extra Example 1: Tangents & Circumscribed Polygons 5:50 
   Extra Example 2: Tangents & Circumscribed Polygons 8:35 
   Extra Example 3: Tangents & Circumscribed Polygons 11:50 
   Extra Example 4: Tangents & Circumscribed Polygons 15:43 
  Secants, Tangents, & Angle Measures 27:50
   Intro 0:00 
   Secant 0:08 
    Secant 0:09 
   Secant and Tangent 0:49 
    Secant and Tangent 0:50 
   Interior Angles 2:56 
    Secants & Interior Angles 2:57 
   Exterior Angles 7:21 
    Secants & Exterior Angles 7:22 
   Extra Example 1: Secants, Tangents, & Angle Measures 10:53 
   Extra Example 2: Secants, Tangents, & Angle Measures 13:31 
   Extra Example 3: Secants, Tangents, & Angle Measures 19:54 
   Extra Example 4: Secants, Tangents, & Angle Measures 22:29 
  Special Segments in a Circle 23:08
   Intro 0:00 
   Chord Segments 0:05 
    Chord Segments 0:06 
   Secant Segments 1:36 
    Secant Segments 1:37 
   Tangent and Secant Segments 4:10 
    Tangent and Secant Segments 4:11 
   Extra Example 1: Special Segments in a Circle 5:53 
   Extra Example 2: Special Segments in a Circle 7:58 
   Extra Example 3: Special Segments in a Circle 11:24 
   Extra Example 4: Special Segments in a Circle 18:09 
  Equations of Circles 27:01
   Intro 0:00 
   Equation of a Circle 0:06 
    Standard Equation of a Circle 0:07 
    Example 1: Equation of a Circle 0:57 
    Example 2: Equation of a Circle 1:36 
   Extra Example 1: Determine the Coordinates of the Center and the Radius 4:56 
   Extra Example 2: Write an Equation Based on the Given Information 7:53 
   Extra Example 3: Graph Each Circle 16:48 
   Extra Example 4: Write the Equation of Each Circle 19:17 
X. Polygons & Area
  Polygons 27:24
   Intro 0:00 
   Polygons 0:10 
    Polygon vs. Not Polygon 0:18 
   Convex and Concave 1:46 
    Convex vs. Concave Polygon 1:52 
   Regular Polygon 4:04 
    Regular Polygon 4:05 
   Interior Angle Sum Theorem 4:53 
    Triangle 5:03 
    Quadrilateral 6:05 
    Pentagon 6:38 
    Hexagon 7:59 
    20-Gon 9:36 
   Exterior Angle Sum Theorem 12:04 
    Exterior Angle Sum Theorem 12:05 
   Extra Example 1: Drawing Polygons 13:51 
   Extra Example 2: Convex Polygon 15:16 
   Extra Example 3: Exterior Angle Sum Theorem 18:21 
   Extra Example 4: Interior Angle Sum Theorem 22:20 
  Area of Parallelograms 17:46
   Intro 0:00 
   Parallelograms 0:06 
    Definition and Area Formula 0:07 
   Area of Figure 2:00 
    Area of Figure 2:01 
   Extra Example 1:Find the Area of the Shaded Area 3:14 
   Extra Example 2: Find the Height and Area of the Parallelogram 6:00 
   Extra Example 3: Find the Area of the Parallelogram Given Coordinates and Vertices 10:11 
   Extra Example 4: Find the Area of the Figure 14:31 
  Area of Triangles Rhombi, & Trapezoids 20:31
   Intro 0:00 
   Area of a Triangle 0:06 
    Area of a Triangle: Formula and Example 0:07 
   Area of a Trapezoid 2:31 
    Area of a Trapezoid: Formula 2:32 
    Area of a Trapezoid: Example 6:55 
   Area of a Rhombus 8:05 
    Area of a Rhombus: Formula and Example 8:06 
   Extra Example 1: Find the Area of the Polygon 9:51 
   Extra Example 2: Find the Area of the Figure 11:19 
   Extra Example 3: Find the Area of the Figure 14:16 
   Extra Example 4: Find the Height of the Trapezoid 18:10 
  Area of Regular Polygons & Circles 36:43
   Intro 0:00 
   Regular Polygon 0:08 
    SOHCAHTOA 0:54 
    30-60-90 Triangle 1:52 
    45-45-90 Triangle 2:40 
   Area of a Regular Polygon 3:39 
    Area of a Regular Polygon 3:40 
   Are of a Circle 7:55 
    Are of a Circle 7:56 
   Extra Example 1: Find the Area of the Regular Polygon 8:22 
   Extra Example 2: Find the Area of the Regular Polygon 16:48 
   Extra Example 3: Find the Area of the Shaded Region 24:11 
   Extra Example 4: Find the Area of the Shaded Region 32:24 
  Perimeter & Area of Similar Figures 18:17
   Intro 0:00 
   Perimeter of Similar Figures 0:08 
    Example: Scale Factor & Perimeter of Similar Figures 0:09 
   Area of Similar Figures 2:44 
    Example:Scale Factor & Area of Similar Figures 2:55 
   Extra Example 1: Complete the Table 6:09 
   Extra Example 2: Find the Ratios of the Perimeter and Area of the Similar Figures 8:56 
   Extra Example 3: Find the Unknown Area 12:04 
   Extra Example 4: Use the Given Area to Find AB 14:26 
  Geometric Probability 38:40
   Intro 0:00 
   Length Probability Postulate 0:05 
    Length Probability Postulate 0:06 
   Are Probability Postulate 2:34 
    Are Probability Postulate 2:35 
   Are of a Sector of a Circle 4:11 
    Are of a Sector of a Circle Formula 4:12 
    Are of a Sector of a Circle Example 7:51 
   Extra Example 1: Length Probability 11:07 
   Extra Example 2: Area Probability 12:14 
   Extra Example 3: Area Probability 17:17 
   Extra Example 4: Area of a Sector of a Circle 26:23 
XI. Solids
  Three-Dimensional Figures 23:39
   Intro 0:00 
   Polyhedrons 0:05 
    Polyhedrons: Definition and Examples 0:06 
    Faces 1:08 
    Edges 1:55 
    Vertices 2:23 
   Solids 2:51 
    Pyramid 2:54 
    Cylinder 3:45 
    Cone 4:09 
    Sphere 4:23 
   Prisms 5:00 
     Rectangular, Regular, and Cube Prisms 5:02 
   Platonic Solids 9:48 
    Five Types of Regular Polyhedra 9:49 
   Slices and Cross Sections 12:07 
    Slices 12:08 
    Cross Sections 12:47 
   Extra Example 1: Name the Edges, Faces, and Vertices of the Polyhedron 14:23 
   Extra Example 2: Determine if the Figure is a Polyhedron and Explain Why 17:37 
   Extra Example 3: Describe the Slice Resulting from the Cut 19:12 
   Extra Example 4: Describe the Shape of the Intersection 21:25 
  Surface Area of Prisms and Cylinders 38:50
   Intro 0:00 
   Prisms 0:06 
    Bases 0:07 
    Lateral Faces 0:52 
    Lateral Edges 1:19 
    Altitude 1:58 
   Prisms 2:24 
    Right Prism 2:25 
    Oblique Prism 2:56 
   Classifying Prisms 3:27 
    Right Rectangular Prism 3:28 
     4:55 
    Oblique Pentagonal Prism 6:26 
    Right Hexagonal Prism 7:14 
   Lateral Area of a Prism 7:42 
    Lateral Area of a Prism 7:43 
   Surface Area of a Prism 13:44 
    Surface Area of a Prism 13:45 
   Cylinder 16:18 
    Cylinder: Right and Oblique 16:19 
   Lateral Area of a Cylinder 18:02 
    Lateral Area of a Cylinder 18:03 
   Surface Area of a Cylinder 20:54 
    Surface Area of a Cylinder 20:55 
   Extra Example 1: Find the Lateral Area and Surface Are of the Prism 21:51 
   Extra Example 2: Find the Lateral Area of the Prism 28:15 
   Extra Example 3: Find the Surface Area of the Prism 31:57 
   Extra Example 4: Find the Lateral Area and Surface Area of the Cylinder 34:17 
  Surface Area of Pyramids and Cones 26:10
   Intro 0:00 
   Pyramids 0:07 
    Pyramids 0:08 
   Regular Pyramids 1:52 
    Regular Pyramids 1:53 
   Lateral Area of a Pyramid 4:33 
    Lateral Area of a Pyramid 4:34 
   Surface Area of a Pyramid 9:19 
    Surface Area of a Pyramid 9:20 
   Cone 10:09 
    Right and Oblique Cone 10:10 
   Lateral Area and Surface Area of a Right Cone 11:20 
    Lateral Area and Surface Are of a Right Cone 11:21 
   Extra Example 1: Pyramid and Prism 13:11 
   Extra Example 2: Find the Lateral Area of the Regular Pyramid 15:00 
   Extra Example 3: Find the Surface Area of the Pyramid 18:29 
   Extra Example 4: Find the Lateral Area and Surface Area of the Cone 22:08 
  Volume of Prisms and Cylinders 21:59
   Intro 0:00 
   Volume of Prism 0:08 
    Volume of Prism 0:10 
   Volume of Cylinder 3:38 
    Volume of Cylinder 3:39 
   Extra Example 1: Find the Volume of the Prism 5:10 
   Extra Example 2: Find the Volume of the Cylinder 8:03 
   Extra Example 3: Find the Volume of the Prism 9:35 
   Extra Example 4: Find the Volume of the Solid 19:06 
  Volume of Pyramids and Cones 22:02
   Intro 0:00 
   Volume of a Cone 0:08 
    Volume of a Cone: Example 0:10 
   Volume of a Pyramid 3:02 
    Volume of a Pyramid: Example 3:03 
   Extra Example 1: Find the Volume of the Pyramid 4:56 
   Extra Example 2: Find the Volume of the Solid 6:01 
   Extra Example 3: Find the Volume of the Pyramid 10:28 
   Extra Example 4: Find the Volume of the Octahedron 16:23 
  Surface Area and Volume of Spheres 14:46
   Intro 0:00 
   Special Segments 0:06 
    Radius 0:07 
    Chord 0:31 
    Diameter 0:55 
    Tangent 1:20 
   Sphere 1:43 
    Plane & Sphere 1:44 
    Hemisphere 2:56 
   Surface Area of a Sphere 3:25 
    Surface Area of a Sphere 3:26 
   Volume of a Sphere 4:08 
    Volume of a Sphere 4:09 
   Extra Example 1: Determine Whether Each Statement is True or False 4:24 
   Extra Example 2: Find the Surface Area of the Sphere 6:17 
   Extra Example 3: Find the Volume of the Sphere with a Diameter of 20 Meters 7:25 
   Extra Example 4: Find the Surface Area and Volume of the Solid 9:17 
  Congruent and Similar Solids 16:06
   Intro 0:00 
   Scale Factor 0:06 
    Scale Factor: Definition and Example 0:08 
   Congruent Solids 1:09 
    Congruent Solids 1:10 
   Similar Solids 2:17 
    Similar Solids 2:18 
   Extra Example 1: Determine if Each Pair of Solids is Similar, Congruent, or Neither 3:35 
   Extra Example 2: Determine if Each Statement is True or False 7:47 
   Extra Example 3: Find the Scale Factor and the Ratio of the Surface Areas and Volume 10:14 
   Extra Example 4: Find the Volume of the Larger Prism 12:14 
XII. Transformational Geometry
  Mapping 14:12
   Intro 0:00 
   Transformation 0:04 
    Rotation 0:32 
    Translation 1:03 
    Reflection 1:17 
    Dilation 1:24 
   Transformations 1:45 
    Examples 1:46 
   Congruence Transformation 2:51 
    Congruence Transformation 2:52 
   Extra Example 1: Describe the Transformation that Occurred in the Mappings 3:37 
   Extra Example 2: Determine if the Transformation is an Isometry 5:16 
   Extra Example 3: Isometry 8:16 
  Reflections 23:17
   Intro 0:00 
   Reflection 0:05 
    Definition of Reflection 0:06 
    Line of Reflection 0:35 
    Point of Reflection 1:22 
   Symmetry 1:59 
    Line of Symmetry 2:00 
    Point of Symmetry 2:48 
   Extra Example 1: Draw the Image over the Line of Reflection and the Point of Reflection 3:45 
   Extra Example 2: Determine Lines and Point of Symmetry 6:59 
   Extra Example 3: Graph the Reflection of the Polygon 11:15 
   Extra Example 4: Graph the Coordinates 16:07 
  Translations 18:43
   Intro 0:00 
   Translation 0:05 
    Translation: Preimage & Image 0:06 
    Example 0:56 
   Composite of Reflections 6:28 
    Composite of Reflections 6:29 
   Extra Example 1: Translation 7:48 
   Extra Example 2: Image, Preimage, and Translation 12:38 
   Extra Example 3: Find the Translation Image Using a Composite of Reflections 15:08 
   Extra Example 4: Find the Value of Each Variable in the Translation 17:18 
  Rotations 21:26
   Intro 0:00 
   Rotations 0:04 
    Rotations 0:05 
   Performing Rotations 2:13 
    Composite of Two Successive Reflections over Two Intersecting Lines 2:14 
    Angle of Rotation: Angle Formed by Intersecting Lines 4:29 
   Angle of Rotation 5:30 
    Rotation Postulate 5:31 
   Extra Example 1: Find the Rotated Image 7:32 
   Extra Example 2: Rotations and Coordinate Plane 10:33 
   Extra Example 3: Find the Value of Each Variable in the Rotation 14:29 
   Extra Example 4: Draw the Polygon Rotated 90 Degree Clockwise about P 16:13 
  Dilation 37:06
   Intro 0:00 
   Dilations 0:06 
    Dilations 0:07 
   Scale Factor 1:36 
    Scale Factor 1:37 
    Example 1 2:06 
    Example 2 6:22 
   Scale Factor 8:20 
    Positive Scale Factor 8:21 
    Negative Scale Factor 9:25 
    Enlargement 12:43 
    Reduction 13:52 
   Extra Example 1: Find the Scale Factor 16:39 
   Extra Example 2: Find the Measure of the Dilation Image 19:32 
   Extra Example 3: Find the Coordinates of the Image with Scale Factor and the Origin as the Center of Dilation 26:18 
   Extra Example 4: Graphing Polygon, Dilation, and Scale Factor 32:08