CK-12 Foundation
Ck 12: Elem Math: Overview Sum of the Angles of a Triangle
[Free Registration/Login may be required to access all resource tools.] Students watch a video overview on funding the sum of angles in a triangle.
CK-12 Foundation
Ck 12: Elem Math: Overview of Special Triangles
[Free Registration/Login may be required to access all resource tools.] Students watch a video overview on how to find missing angles in triangles.
Sophia Learning
Sophia: Angles of a Triangle
This video tutorial demonstrates how to find the interior and exterior angles of a triangle.
Khan Academy
Khan Academy: Vi Hart: Doodling in Math: Triangle Party: Triangles!
Video exploring triangles and illustrating fractal concepts such as the Koch snowflake. [4:25]