Instructional Video
Khan Academy

Khan Academy: Find Measure of Vertical Angles

7th Standards
Demonstrates how to find unknown angles for two intersecting lines when some angle information is given. [3:00]
Instructional Video
Virtual Nerd

Virtual Nerd: What Are Vertical Angles?

9th - 10th Standards
Vertical angles are always congruent to one another. Take a look at this tutorial to learn about and see how to identify vertical angles. [4:07]
Instructional Video
Virtual Nerd

Virtual Nerd: What Are Complementary Angles?

9th - 10th Standards
Complementary angles always add up to 90 degrees. Watch this tutorial to learn about complementary angles and see how to use this knowledge to solve a problem involving these special types of angles. [3:20]
Instructional Video
Virtual Nerd

Virtual Nerd: How Do You Use Complementary Angles to Find a Missing Angle?

9th - 10th Standards
View this tutorial to see how to use what you know about complementary angles to find a missing angle measurement. [3:20]
Instructional Video
Virtual Nerd

Virtual Nerd: What Are Supplementary Angles?

9th - 10th Standards
Take a look at this tutorial as it introduces you to supplementary angles and shows you how to use them to solve for a missing angle measurement. [3:20]
Instructional Video
Khan Academy

Khan Academy: Geometry: Introduction to Angles (Old)

9th - 10th Standards
Defines an angle, complementary angles, supplementary angles, and relates reflex angle measures to degress in a circle. [9:55]
Instructional Video
Khan Academy

Khan Academy: Geometry: Complementary and Supplementary Angles

9th - 10th Standards
Defines and gives examples of complementary angles, supplementary angles, and adjacent angles. Practice problems available. [8:31]
Instructional Video
Khan Academy

Khan Academy: Angles: Complementary and Supplementary Angles

9th - 10th Standards
Basics of complementary, supplementary, adjacent and straight angles. Also touching on what it means to be perpendicular.
Instructional Video
Khan Academy

Khan Academy: Sal's Old Angle Videos: Angle Game (Part 2)

9th - 10th Standards
Solving for unknown angle measures using knowledge of different angle relationships and the triangle sum theorem.
Instructional Video
Khan Academy

Khan Academy: Sal's Old Angle Videos: The Angle Game

9th - 10th Standards
Solving for unknown angle measures using knowledge of different angle relationships and the triangle sum theorem.
Instructional Video
Khan Academy

Khan Academy: Geometry: Angles (Part 2)

9th - 10th Standards
Describes complementary and supplementary angles. Explains how to use properties of complementary and supplementary angles to solve for missing angle measures. Introduces idea that vertical angles (opposite angles) are congruent. [9:05]
Instructional Video
Khan Academy

Khan Academy: Angles (Part 2)

9th - 10th Standards
Describes complementary and supplementary angles. Explains how to use properties of complementary and supplementary angles to solve for missing angle measures. Introduces idea that vertical angles (opposite angles) are congruent. [9:05]
Instructional Video
Math Mammoth

Math Mammoth: Angles in a Triangle Add Up to 180 Degrees: Exercises and Proof

6th - 8th Standards
Demonstrates how to solve problems where one angle of a triangle is unknown and how to draw an isosceles triangle with the given properties. This is followed by a proof of the angle-sum theorem. [9:18]
Instructional Video
Virtual Nerd

Virtual Nerd: How Do You Find Missing Angles in a Transversal Diagram?

9th - 10th Standards
Take a look at this tutorial to see how to find all the missing angle measurements by identifying vertical, corresponding, adjacent, and alternate exterior angles. [4:43]
Instructional Video
Virtual Nerd

Virtual Nerd: How Do You Use Supplementary Angles to Find a Missing Angle?

9th - 10th Standards
In this tutorial, you'll see how to use your knowledge of supplementary angles to set up an equation and solve for a missing angle measurement. [3:41]
Instructional Video
Khan Academy

Khan Academy: Geometry: Finding More Angles

9th - 10th Standards
Solving for measures of the angles in a triangle using algebra, the triangle sum theorem, and properties of angles created by a transversal that cuts parallel lines. [6:05]
Instructional Video
Khan Academy

Khan Academy: Geometry: Triangle Angle Example 1

9th - 10th Standards
Explains how to use the triangle sum theorem to solve for missing angle measures in a triangle. Also addresses the relationship between the measure of an exterior angle of a triangle and the measures of the remote interior angles. This...
Instructional Video
Khan Academy

Khan Academy: Angles (Part 3)

9th - 10th Standards
Identifies and defines the types of angles formed by parallel lines cut by a transversal and the relationship of their measures.
Instructional Video
Khan Academy

Khan Academy: Proof Vertical Angles Are Equal

9th - 10th Standards
Proving that vertical angles are equal
Instructional Video
Khan Academy

Khan Academy: Geometry: Angles Formed Between Transversals and Parallel Lines

9th - 10th Standards
Explains the relationship between the measures of angles formed when parallel lines are cut by a transversal based on relationships of corresponding, vertical, and supplementary angles. [7:53]
Instructional Video
Khan Academy

Khan Academy: Geometry: Angles (Part 3)

9th - 10th Standards
Identifies and defines the types of angles formed by parallel lines cut by a transversal and the relationship of their measures. Discusses Triangle Sum Theorem. [9:48]
Instructional Video
Art of Problem Solving

Art of Problem Solving: Introduction to Angles

9th - 10th Standards
Video tutorial uses examples to provide an introduction to angles including right, acute, and obtuse angles. [8:22]
Instructional Video
Art of Problem Solving

Art of Problem Solving: Angles in a Triangle Part 2

9th - 10th Standards
Video tutorial uses problems to reinforce understanding of angles in a triangle. (Part 2) [6:23]
Instructional Video
Art of Problem Solving

Art of Problem Solving: Angles in a Triangle Part 1

9th - 10th Standards
Video tutorial uses problems to reinforce understanding that the angles in a triangle always add up to 180 degrees. (Part 1) [3:55]