High School Mathematics: Geometry

Video Lectures

Displaying all 86 video lectures.
Lecture 1
Points Lines & Planes in Geometry
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Points Lines & Planes in Geometry
I introduce Points, Lines, and Planes along with many definitions like collinear and coplanar points to begin our studies of Geometry. Parts D and E of the last example should read is there a plane in the solid that contains these 3 vertices, not if they are coplanar. Asking if they are coplanar is the same type of error I corrected early in the video. Three points define a plane.
EXAMPLES at 16:35

Check out http://www.ProfRobBob.com, there you will find my lessons organized by class/subject and then by topics within each class.
Lecture 2
More Postulates & Theorems Points, Lines, & Planes
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More Postulates & Theorems Points, Lines, & Planes
I introduce 5 more postulates relating to points, lines, and planes. These postulates are then used to prove the first three theorems in Geometry. Theorem 1, If 2 lines intersect, then they intersect in exactly one point. Theorem 2, Through a line and a point not in the line there is exactly one plane. Theorem 3, If 2 lines intersect, then exactly 1 plane contains the lines.
EXAMPLES at 5:41 12:35 19:50

Check out http://www.ProfRobBob.com, there you will find my lessons organized by class/subject and then by topics within each class.
Lecture 3
Segment, Ray, Distance on a Number Line
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Segment, Ray, Distance on a Number Line
I introduce the basic geometric figures of segments, rays, and distance on a number line. This lecture includes discussions about the Ruler Postulate, Segment Addition Postulate, Congruency is defined, Midpoint of a Segment, and finally Bisector of a Segment.
Lecture 4
Introduction to Angles
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Introduction to Angles
I introduce the basic structure of angles in Geometry, how to name them based on points, and size such as acute and obtuse. I also introduce the Protractor Postulate, Angle addition Postulate, define congruent angles, angle bisector, and adjacent angles.
EXAMPLES at 12:20 18:30 22:58
Lecture 5
Special Angle Pairs
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Special Angle Pairs
EXAMPLES start at 9:27
I introduce Adjacent Angles, Vertical Angles, Supplementary Angles, Linear Pair, and Complementary Angles in Geometry.
Lecture 6
Basic Constructions Segment & Angle
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Basic Constructions Segment & Angle
I show you how to construct a congruent segment and a congruent angle using just a straight edge and a compass.
Lecture 7
Angle and Segment Bisector Constructions
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Angle and Segment Bisector Constructions
I give you the steps and demonstrations on how to construct a perpendicular bisector of a segment and an angle bisector with a compass and a straight edge.
Lecture 8
Distance Formula & Pythagorean Theorem
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Distance Formula & Pythagorean Theorem
I introduce the distance formula and show it's relationship to the Pythagorean Theorem. This video includes three examples of finding the distance between two points.
EXAMPLES at 2:54 14:21 17:41
Lecture 9
Midpoint Formula
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Midpoint Formula
I introduce the midpoint formula and work thought three examples to your understanding. The first two examples are finding a midpoint, the second involves fractions. The last example shows you how to find an unknown endpoint when you know the midpoint and one endpoint of the segment.
EXAMPLES at 2:21 9:22 15:00
Lecture 10
Perimeter of a Plane Region
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Perimeter of a Plane Region
I introduce finding the perimeter of a 2 dimensional plane region and work through 6 examples to help your studies.
EXAMPLES at 5:52 7:05 14:38 15:22 22:37 26:07
Lecture 11
Area of a Plane Region
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Area of a Plane Region
I work through multiple examples of finding the area of 2 dimentional plane areas.
EXAMPLES at 6:10 10:55 12:28 15:58 19:59
Lecture 12
Deductive Reasoning If Then Statements
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Deductive Reasoning If Then Statements
I introduce deductive reasoning by introducing the structure of "if, then" statements. I explain conditional statements, converse statements, bi-conditional statements, inverse statements, and finally contrapositive statements.
Lecture 13
Intro to 2 Column Geometry Proofs
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Intro to 2 Column Geometry Proofs
I introduce the structure of 2 column proofs and then remind you of the Properties of Equality you learned in Algebra. I finish by working through three examples.
EXAMPLES at 13:10 17:09 23:43

Check out http://www.ProfRobBob.com, there you will find my lessons organized by class/subject and then by topics within each class.
Lecture 14
Congruent Angles
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Congruent Angles
I introduce geometry theorems that involve congruent angles such as vertical angles. I work through a couple of examples and do a 2 column proof of the Vertical Angle Theorem.
EXAMPLES at 2:08 6:54 10:40
Lecture 15
Parallel Lines & Skew Lines, Angles formed by a Transversal
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Parallel Lines & Skew Lines, Angles formed by a Transversal
I define and show you how to identify Skew and Parallel lines in a drawing. I then discuss the types of angles you have when 2 or more lines are cut by a transversal.
Lecture 16
Parallel Lines & Transversal Angles
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Parallel Lines & Transversal Angles
I introduce the properties of angles that are formed when 2 parallel lines are intersected by a transversal. These angles include Corresponding, Alternate Interior, Alternate Exterior, and Same-Side Interior angles. I finish with 5 examples, the last of which is a proof involving parallel lines. EXAMPLES at 2:00 6:06 11:13 14:10
Lecture 17
Proving Lines Parallel
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Proving Lines Parallel
We take another look at parallel lines being cut by a transversal. I work through two examples where we are proving the lines that were cut by a transversal are parallel.
EXAMPLES at 4:51 13:04
Lecture 18
Parallel & Perpendicular Lines Proof
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Parallel & Perpendicular Lines Proof
I introduce 2 more theorems that can verify that 2 lines are parallel. Each of these two theorems are proven with 2 column proofs. EXAMPLES at 0:04 7:54
Lecture 19
Angles of Triangles and Parallel Lines
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Angles of Triangles and Parallel Lines
I introduce the theorem that state the interior sum of the angles of a triangle add up to 180 degrees and show how this is true with parallel lines. The second theorem I cover explains how an exterior angle of a triangle is equal to the sum of the 2 interior remote angles.
EXAMPLES at 6:34 9:00 14:46 19:43 23:32
Lecture 20
Graphing Lines in Slope-Intercept form y=mx+b
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Graphing Lines in Slope-Intercept form y=mx+b
I introduce how to graph a line in slope intercept form. I also discuss graphing vertical and horizontal lines.

Please check out my other lessons about Linear Functions:
Graphing Lines with x-Intercepts and y-Intercepts
https://www.youtube.com/watch?v=KtgddI4qIok
Slope and Equations of Lines
https://www.youtube.com/watch?v=xf8-BEdoSss
Equations of Lines and Graphing
https://www.youtube.com/watch?v=Wmi1EysOHUQ
Equations of parallel and perpendicular lines
https://www.youtube.com/watch?v=ECljEiIgX_M
Linear Functions, their Attributes, & Interpreting Slope and y-Intercept
https://www.youtube.com/watch?v=qbNTy0oMq1c

Check out www.ProfRobBob.com, there you will find my lessons organized by class/subject and then by topics within each class.
Lecture 21
Equations of Lines and Graphing
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Equations of Lines and Graphing
Continued discussion about equations of lines and the three equation forms. Graphing of linear functions also included.
Please check out my other lessons about Linear Functions:
Graphing Lines in Slope-Intercept form y=mx+b
https://www.youtube.com/watch?v=xyVJZKu7Euw
Graphing lines using X & Y Intercepts
https://www.youtube.com/watch?v=KtgddI4qIok
Slope and Equations of Lines
https://www.youtube.com/watch?v=xf8-BEdoSss
Equations of parallel and perpendicular lines
https://www.youtube.com/watch?v=ECljEiIgX_M
Regression Lines and Correlation with TI-84
https://www.youtube.com/watch?v=L_h7nqNqgPs
Linear Functions, their Attributes, & Interpreting Slope and y-Intercept
https://www.youtube.com/watch?v=qbNTy0oMq1c

Check out www.ProfRobBob.com, there you will find my lessons organized by class/subject and then by topics within each class.
Lecture 22
Rate of Change Slope & Point Slope Equation of Lines
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Rate of Change Slope & Point Slope Equation of Lines
Introduction to finding slope and graphing lines.

Please check out my other lessons about Linear Functions:
Graphing Lines in Slope-Intercept form y=mx+b
https://www.youtube.com/watch?v=xyVJZKu7Euw
Graphing lines using X & Y Intercepts
https://www.youtube.com/watch?v=KtgddI4qIok
Equations of Lines and Graphing
https://www.youtube.com/watch?v=Wmi1EysOHUQ
Equations of parallel and perpendicular lines
https://www.youtube.com/watch?v=ECljEiIgX_M
Regression Lines and Correlation with TI-84
https://www.youtube.com/watch?v=L_h7nqNqgPs
Linear Functions, their Attributes, & Interpreting Slope and y-Intercept
https://www.youtube.com/watch?v=qbNTy0oMq1c

Check out www.ProfRobBob.com, there you will find my lessons organized by class/subject and then by topics within each class.
Lecture 23
Equations of Parallel and Perpendicular Lines
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Equations of Parallel and Perpendicular Lines
An introduction to finding the equations of lines that pass through a point and are parallel or perpendicular to a given line.
Please check out my other lessons about Linear Functions:
Graphing Lines in Slope-Intercept form y=mx+b
https://www.youtube.com/watch?v=xyVJZKu7Euw
Graphing lines using X & Y Intercepts
https://www.youtube.com/watch?v=KtgddI4qIok
Slope and Equations of Lines
https://www.youtube.com/watch?v=xf8-BEdoSss
Equations of Lines and Graphing
https://www.youtube.com/watch?v=Wmi1EysOHUQ
Regression Lines and Correlation with TI-84
https://www.youtube.com/watch?v=L_h7nqNqgPs
Linear Functions, their Attributes, & Interpreting Slope and y-Intercept
https://www.youtube.com/watch?v=qbNTy0oMq1c

Check out www.ProfRobBob.com, there you will find my lessons organized by class/subject and then by topics within each class.
Lecture 24
Congruent Polygons & Third Angle Theorem
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Congruent Polygons & Third Angle Theorem
I define congruent polygons and prove the Third Angle Theorem. EXAMPLES AT 4:28 10:40 16:24 22:25
Lecture 25
Congruent Triangles SSS SAS
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Congruent Triangles SSS SAS
I introduce the Side-Side-Side Postulate and Side-Angle-Side Postulate and work through 4 2 column proofs showing you how these can prove 2 triangles are congruent. EXAMPLES AT 0:55 6:04 11:39 14:42 16:43

Check out http://www.ProfRobBob.com, there you will find my lessons organized by class/subject and then by topics within each class.
Lecture 26
Congruent Triangles ASA AAS
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Congruent Triangles ASA AAS
I introduce the ASA Postulate and the AAS Theorem for proving two triangles are congruent and work through 4 examples of including 2 column proofs. EXAMPLES AT 0:50 7:19 9:45 13:38
Lecture 27
Non Congruence Theorems AAA SSA
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Non Congruence Theorems AAA SSA
Now that we know 4 ways to prove two triangles are congruent, lets look at two non-congruence theorems. Students often use these to prove triangles are congruent which is incorrect.
Lecture 28
CPCTC Corresponding Parts of Congruent Triangles are Congruent
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CPCTC Corresponding Parts of Congruent Triangles are Congruent
I introduce "Congruent Parts of Congruent Triangles are Congruent" and work through two proofs that used this concept. EXAMPLES AT 0:10 4:26
Lecture 29
Isosceles & Equilateral Triangle Properties
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Isosceles & Equilateral Triangle Properties
I introduce 2 theorems about the properties of Isosceles and Equilateral Triangles. These theorems discuss how the base angles are congruent and that the bisector of the vertex is also a perpendicular bisector of the base. This video includes 2 proofs and 2 algebraic examples. EXAMPLES AT 0:05 9:06 15:37 22:45
Lecture 30
Equilateral Triangle / Equiangular Triangle
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Equilateral Triangle / Equiangular Triangle
I introduce and define equilateral triangles and equiangular triangles. I then work through 3 examples involving the lengths of sides and angles. EXAMPLES AT 2:55 8:14 15:52
Lecture 31
Congruent Right Triangles HL Hypotenuse Leg Theorem
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Congruent Right Triangles HL Hypotenuse Leg Theorem
I introduce the Hypotenuse Leg Theorem or HL and prove it in a 2 column proof. I also work through three examples using this theorem.EXAMPLES AT 11:10 13:00 14:20
Second Version of Proof at 21:03
Lecture 32
Triangle Midsegment Theorem
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Triangle Midsegment Theorem
I introduce and work through many examples involving the Triangle Midsegment Theorem. When a segment connects the midpoints of two sides of a triangle, that midsegment is half the length of the third side and also parallel to that third side. EXAMPLES AT 1:05 10:42 13:55
Lecture 33
Proving Midsegment Theorem
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Proving Midsegment Theorem
Using the midpoint, slope, and distance formulas I prove the Midsegment Theorem which states a segment that connect the midpoints of 2 sides of a triangle is parallel and half the length of the third side.
Lecture 34
Perpendicular Bisector Theorem
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Perpendicular Bisector Theorem
I introduce the Perpendicular Bisector Theorem and the Converse Theorem and prove both. I finish by working through three examples. EXAMPLES AT 0:34 11:55 14:38 20:15
Lecture 35
Angle Bisector Theorem
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Angle Bisector Theorem
I introduce the Angle Bisector Theorem and prove it, introduce the Converse of the Angle Bisector Theorem, and finish by working through two examples. EXAMPLES AT 0:20 9:40 15:19
Lecture 36
Triangle Perpendicular Bisectors & Circumcenter
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Triangle Perpendicular Bisectors & Circumcenter
I introduce the Perpendicular Bisector Theorem in triangles. We discuss how the point of concurrency is the center of the circumcenter. The circumcenter is the center of the circle that circumscribed the triangle. I finish by working through two examples of finding the circumcenter of a triangle given its three vertices. EXAMPLES AT 3:56 9:36 13:47
Lecture 37
Triangle Angle Bisectors & Incenter
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Triangle Angle Bisectors & Incenter
I introduce Concurrency of Angle Bisectors in Triangles and discuss how they meet at the center of the inscribed circle. EXAMPLES AT 2:23 6:28
Lecture 38
Medians of Triangles & Centroid
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Medians of Triangles & Centroid
I introduce Medians in Triangles and their point of concurrency...the centroid. I finish by working through three example dealing with the centroid and the ratio of the median segments. EXAMPLES AT 5:43 7:47 12:48
Lecture 39
Altitudes of Triangles and Orthocenter
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Altitudes of Triangles and Orthocenter
I introduce altitudes in triangles and point of concurrency, the orthocenter. I finish by working through two examples, the last of which finding the orthocenter given the three vertices of a triangle. EXAMPLES AT 7:10 10:31
Lecture 40
Triangle Inequality Theorem
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Triangle Inequality Theorem
I introduce Inequalities in 1 Triangle in which we look at how the lengths of the sides are related to the size of the angles that are opposite those sides. EXAMPLES AT 2:34 6:04 9:55 11:43 14:25 15:30
At minute 2:07 I misspoke, 20+30 is 50 of course:D
Lecture 41
Hinge Theorem Inequalities 2 Triangles
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Hinge Theorem Inequalities 2 Triangles
I introduce the Hinge Theorem which allows us to look at the size relationship between the angles and sides within multiple triangles. I work through many examples in this video. EXAMPLES AT 1:40 2:28 3:30 4:48 5:32 8:52
Lecture 42
Polygon Angle Sum Theorems
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Polygon Angle Sum Theorems
I introduce Polygon Angle Sum Theorems, not Polynomial Angle Sum Theorem which isn't even a theorem! This includes finding the Sum of the Interior Angles of a Polygon and the Sum of the Exterior Angles. I also talk about finding the individual interior and exterior angles of Regular Polygons...after I define what a Regular Polygon is:) EXAMPLES AT 3:30 4:29 5:38 7:00 10:40 14:18 15:22 17:26
I do not know why I wrote Polynomial Angle Sum Theorem???!!! Too many hours working between teaching and YouTube I guess.
Lecture 43
Properties of Parallelograms
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Properties of Parallelograms
I introduce the Properties of Parallelograms...the opposite sides are equal, the opposite angles are equal, the consecutive angles are supplementary, and the diagonals bisect each other. I work through four algebraic examples in this video at 4:28 14:30
Lecture 44
Proving Quadrilaterals are Parallelograms
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Proving Quadrilaterals are Parallelograms
We work with the converse of the theorems we learned in the last video to prove, or make sure, that quadrilaterals are parallelogram. I work through two algebraic examples and one two column proof. EXAMPLES AT 2:33 8:43 12:22
Lecture 45
Rhombuses, Rectangles, and Squares
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Rhombuses, Rectangles, and Squares
I introduce the properties of Rhombuses, Rectangles, and Squares and finish by working through five examples to help you through your homework.
Rhombus examples 5:39 Rectangle examples 14:05
Lecture 46
More Examples Rhombus & Rectangle
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More Examples Rhombus & Rectangle
I continue my examples with Rhombuses, Rectangles, and Squares. These two algebraic examples require slightly more advanced algebra techniques and a need to check your answers with the original Geometric shape. EXAMPLES AT 0:05 12:01
Lecture 47
Properties of Trapezoids & Mid Segment Theorem
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Properties of Trapezoids & Mid Segment Theorem
I introduce Properties of Trapezoids and the Mid-segment Theorem
EXAMPLES AT 3:56 7:54 13:20
Lecture 48
Properties of Kites
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Properties of Kites
I introduce many properties of Kites, work through three examples of finding missing angles, and finish with a quick two column proof. EXAMPLES 5:55 10:09 12:54 14:46
Lecture 49
Polygons in Coordinate Plane
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Polygons in Coordinate Plane
I work through four examples of classifying type of polygons in the coordinate plane using the distance, slope, and midpoint formulas. EXAMPLES AT 2:22 10:24 15:29 23:13
Lecture 50
Ratios & Proportions
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Ratios & Proportions
I introduce how to set up Ratios and Proportions and then work through a number of examples. EXAMPLES start at 1:34 and 6:28 and 14:44 and 23:29

Check out http://www.ProfRobBob.com, there you will find my lessons organized by class/subject and then by topics within each class.
Lecture 51
Proportions and Similar Polygons / Similar Figures
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Proportions and Similar Polygons / Similar Figures
I work through 5 examples of solving for missing sides of similar polygons. Similar polygons have linear sides, the corresponding angles are congruent, and the corresponding sides are proportional. The equal proportions, or constant ratios of the side lengths, are called the Scale Factor. EXAMPLES at 3:15 6:46 12:17 15:21 17:34 22:24
Lecture 52
Proving Triangles are Similar AA SAS SSS
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Proving Triangles are Similar AA SAS SSS
I introduce the AA Postulate and the SAS & SSS to show you how to prove two triangles are similar. This video includes about 5 examples.
The last word in the definition of SAS for similar triangles should be similar, not congruent.

Check out http://www.ProfRobBob.com, there you will find my lessons organized by class/subject and then by topics within each class.
Lecture 53
Similarity in Right Triangles
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Similarity in Right Triangles
When you drop an altitude from the right angle of a right triangle you get three triangles that are all similar to each other. I explain this and finish by working through three examples in this video.
EXAMPLES at 5:26 9:33 17:06 23:15 28:08
Lecture 54
Side Splitter Theorem Proportions in Triangles
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Side Splitter Theorem Proportions in Triangles
I introduce the Side Splitter Theorem for triangles and its corollary that applies to parallel lines intsecting multiple transversals. I work through two algebra examples involving proportions.
EXAMPLES at 1:34 6:23
Lecture 55
Proportions in Triangles Angle Bisector
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Proportions in Triangles Angle Bisector
I introduce the Triangle Angle Bisector Theorem and work through 2 examples to help you set up and solve equal proportions.

Examples at 2:40 8:23
Lecture 56
Pythagorean Theorem
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Pythagorean Theorem
I explain how the Pythagorean Theorem allows you to find the length of an unknown side of a right triangle.
Lecture 57
Converse Pythagorean Theorem & Triples
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Converse Pythagorean Theorem & Triples
I explain the Converse Pythagorean Theorem and what Pythagorean Triples are.
Lecture 58
Special Right Triangles 45-45-90 30-60-90
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Special Right Triangles 45-45-90 30-60-90
I introduce and work through 6 examples of problems involving 30 60 90 triangles and 45 45 90 triangles. All work is done in exact form and not rounded off decimals from a calculator.
EXAMPLES at 3:30 4:47 10:05 11:46 14:05 19:03

Check out http://www.ProfRobBob.com, there you will find my lessons organized by class/subject and then by topics within each class.
Lecture 59
Right Triangle Trigonometry Part 1: Finding Missing Sides
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Right Triangle Trigonometry Part 1: Finding Missing Sides
I introduce evaluating trigonometric functions about a right triangle. We will set up the trig ratios given a right triangle, and find missing angle measures, and sides of right triangles using the pythagorean theorm and the trig functions.

Check out http://www.ProfRobBob.com, there you will find my lessons organized by class/subject and then by topics within each class.
Lecture 60
Right Triangle Trigonometry Part 2: Solving for Acute Angles
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Right Triangle Trigonometry Part 2: Solving for Acute Angles
Link to Part 1 https://www.youtube.com/watch?v=pkjuVZUdcvo
I introduce evaluating trigonometric functions about a right triangle. We will set up the trig ratios given a right triangle, and find missing angle measures, and sides of right triangles using the pythagorean theorm and the trig functions.

Check out http://www.ProfRobBob.com, there you will find my lessons organized by class/subject and then by topics within each class.
Lecture 61
Angle of Elevation and Depression Right Triangle Trig
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Angle of Elevation and Depression Right Triangle Trig
I do some more examples or right triangle trigonometry on Geometry application problems that involve Angle of Depression and/or Elevation.
EXAMPLES at 1:58 8:36 13:06 18:57

Check out http://www.ProfRobBob.com, there you will find my lessons organized by class/subject and then by topics within each class.
Lecture 62
Area Parallelograms and Triangles
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Area Parallelograms and Triangles
I introduce the formulas to find the area of Parallelograms and Triangles. I then work through 6 examples of increasing levels of difficulty.
EXAMPLES at 5:50 8:27 9:45 16:38 20:32 25:42
Lecture 63
Area Trapezoid Rhombus Kite
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Area Trapezoid Rhombus Kite
I work through 6 examples of finding area of Trapezoids, Rhombuses, and Kites.
EXAMPLES at 3:00 8:30 13:37 15:29 20:08 25:24
Lecture 64
Area of Regular Polygon Introduction with Hexagon Examples
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Area of Regular Polygon Introduction with Hexagon Examples
I introduce how to find the area of a regular polygon and finish by working through two examples involving hexagons. The second example is more difficult than the first.
Lecture 65
Area Regular Polygons with Trigonometry
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Area Regular Polygons with Trigonometry
I work through two more examples involving the area of Regular Polygons. These examples require the use of Right Triangle Trigonometry, or Sin Cos Tan, to complete.
Lecture 66
Perimeter and Area Ratios of Similar Figures
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Perimeter and Area Ratios of Similar Figures
I discuss the relationship between the perimeter and area of similar objects. As an example, I show how increasing the perimeter by a scaler multiple of 3 increases the area by 3^2 or nine.
Lecture 67
Circle Intro and Arc Length
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Circle Intro and Arc Length
I introduce many basic definitions that are related to circles and also the area and circumference formula. I then work through many examples examples of naming minor and major arcs, central angles, and finding arc lengths.
EXAMPLES at 9:55 19:50 21:10 25:38
Lecture 68
Sector and Segment Area in Circles
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Sector and Segment Area in Circles
I work through four examples of finding Sector Area and Segment Area of circles.
EXAMPLES at 2:03 6:16 15:23 23:34
Lecture 69
Segment Area in Circles Quicker Methods
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Segment Area in Circles Quicker Methods
Using alternative area formulas for triangles like Heron's Formula and the Area of an Oblique Triangle formula I work through two examples of finding the area of a segment in a circle. EXAMPLES at 3:30 7:49
Lecture 70
Geometric Probabilities Length
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Geometric Probabilities Length
I introduce Geometric Probabilities and work through two examples that involve length. EXAMPLES AT 2:13 6:57 I do some mental math and say that 3/10 is .3333, it is .3 of course.
Lecture 71
Geometric Probabilities Area
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Geometric Probabilities Area
I work through three examples of finding Geometric Probabilities that involve areas of triangles, circles, and a regular polygon:) EXAMPLES AT 1:25 5:33 10:49
Lecture 72
Surface Area of a Right Prism
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Surface Area of a Right Prism
I introduce Right and Oblique Prisms and then work through two examples of finding the Lateral Area and Surface Areas of Right Prisms at 7:07 13:52
Lecture 73
Surface Area Of a Cylinder
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Surface Area Of a Cylinder
I introduce finding the Lateral and Surface Area of Right Cylinders. I finish by working through three examples at 2:54 6:15 13:30
Lecture 74
Surface Area of a Regular Pyramid Non-Trig Examples
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Surface Area of a Regular Pyramid Non-Trig Examples
I introduce finding Surface Area of a Pyramid, vocabulary, and work through three examples to help your understanding and complete your homework.
No Trigonometry is required for these examples at 4:41 9:49 21:30
Lecture 75
Surface Area of a Pyramid with Trigonometry
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Surface Area of a Pyramid with Trigonometry
I work through two examples of finding the surface area of right regular pyramids at 0:51 9:01
Lecture 76
Surface Area of a Cone
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Surface Area of a Cone
I introduce how to find the Surface Area of a Right Cone and finish by working through three examples at 2:29 6:27 10:39
Lecture 77
Volume of a Prism & Volume of a Cylinder
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Volume of a Prism & Volume of a Cylinder
I introduce how to find the Volume of a Prism or Cylinder. I then work through 5 examples in increasing difficulty to help you understand this concept. EXAPMLES at 1:45 4:44 12:53 15:34 17:58
In my last example I keep saying I am working with a bolt, but that would actually be a nut!
Lecture 78
Volume of a Pyramid 3 Examples
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Volume of a Pyramid 3 Examples
I work through three examples of finding the volume of pyramids. Examples at 1:44 7:09 10:43
Lecture 79
Volume of a Cone 3 Examples
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Volume of a Cone 3 Examples
I introduce finding volumes of cones and then work through 3 examples at 2:16 8:42 13:59
Lecture 80
Surface Area of a Sphere & Volume of a Sphere
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Surface Area of a Sphere & Volume of a Sphere
I introduce how to find the Surface Area & Volume of Sphere and work through 4 examples at 2:53 5:51 11:25 18:47
Sorry for the mistake, I misspelled hemisphere.
Lecture 81
Tangent Lines to Circles
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Tangent Lines to Circles
I introduce tangent lines and work through 6 examples to help explain how they relate to circles. Examples at 6:00 7:41 10:18 15:56 18:43 12:31

Check out http://www.ProfRobBob.com, there you will find my lessons organized by class/subject and then by topics within each class.
Lecture 82
Given a Tangent Line & Circle Find the Point of Tangency
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Given a Tangent Line & Circle Find the Point of Tangency
In this lesson I start by setting up the example with you. Then at 15:08 I show you how to find the Point of Tangency when given the equation of the tangent line and a circle. In the first solution I work through the slope formula using the fact that the tangent line and radius are perpendicular. The second method starting at 26:00 I just use straight substitution to solve the system of equations between the tangent line and the circle.

Check out www.ProfRobBob.com, there you will find my lessons organized by class/subject and then by topics within each class.
Lecture 83
Chords Arcs and Diameters in Circle
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Chords Arcs and Diameters in Circle
I introduce the concept of Chords in a circle and then give you 7 theorems that explain the relationships of chords, arcs, diameters, and central angles is circles.
Lecture 84
Inscribed Angles in Circles and Tangent Lines
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Inscribed Angles in Circles and Tangent Lines
I define Inscribed Angles, Inscribed Angles involving Tangent Lines, and 3 Corollaries of Inscribed Angles. I work through five examples to help your understanding.
Lecture 85
Angles in Circles Chords Secants Tangents and Arcs
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Angles in Circles Chords Secants Tangents and Arcs
I introduce how to find angle measures and arc measures in circles created by Secants, Chords, and Tangents that intersect inside or outside of a circle. I work through three multiple part examples to help you in your understanding of how to work these problems.

Check out http://www.ProfRobBob.com, there you will find my lessons organized by class/subject and then by topics within each class.
Lecture 86
Segment Lengths in Circles with Chords, Secants, and Tangents
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Segment Lengths in Circles with Chords, Secants, and Tangents
I introduce how to find segment lengths in circles that are created by the intersection of Chords, Secants, and Tangent lines. I finish by working through 3 examples to help your understanding.