Instructional Video8:42
Curated Video

Triangle Sum Theorem and Exterior Angle Theorem

9th - 12th
In this video, the teacher explains the basics of triangles, including the interior and exterior angles. The lesson covers the triangle sum theorem, using ratios to find angle measures, and the exterior angle theorem. The teacher...
Instructional Video
Khan Academy

Khan Academy: Geometry: Triangle Angle Example 2

9th - 10th Standards
Shows how to find the measure of missing angles using the triangle sum theorem and vertical angles. This video also appears in the Geometry: Triangles strand. [4:55]
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: Triangles: Triangle Angle Example 1

9th - 10th Standards
Explains how to use the triangle sum theorem to solve for missing angle measures in a triangle. A little about exterior angles being the sum of the remote interior angles. Also shows the relationship between the measure of an exterior...
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.