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: Example Involving an Isosceles Triangle and Parallel Lines

9th - 10th Standards
This video demonstrates how to use the triangle sum theorem, properties of isosceles triangles, and special angle pairs formed when parallel lines are cut by a transversal to set up an equation using given algebraic expressions for angle...
Instructional Video
Khan Academy

Khan Academy: Triangles: Triangle Angle Example 2

9th - 10th Standards
Shows how to find the measure of missing angles using the triangle sum theorem and vertical angles.
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]