Khan Academy on a Stick : Sum of Interior Angles of a Polygon

Khan Academy on a Stick

Angles with triangles and polygons

Proof - Sum of Measures of Angles in a Triangle are 180
Triangle Angle Example 1
Triangle Angle Example 2
Triangle Angle Example 3
Challenging Triangle Angle Problem
Proof - Corresponding Angle Equivalence Implies Parallel Lines
Finding more angles
Sum of Interior Angles of a Polygon
Sum of the exterior angles of convex polygon

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