Exterior Angles Theorems: Lesson (Basic Geometry Concepts)

Discover more at www.ck12.org: http://www.ck12.org/geometry/Exterior-Angles-Theorems/

Here you'll learn what an exterior angle is as well as two theorems involving exterior angles: that the sum of the exterior angles is always 360° and that in a triangle, an exterior angle is equal to the sum of its remote interior angles.

This video provides the student with a walkthrough on exterior angle theorems.

This is part of CK-12’s Basic Geometry: Triangles and Congruence. See more at:

1. Triangle Sum Theorem:
http://www.ck12.org/geometry/Triangle-Sum-Theorem/

2. Exterior Angles Theorems:
http://www.ck12.org/geometry/Exterior-Angles-Theorems/

3. Congruent Triangles:
http://www.ck12.org/geometry/Congruent-Triangles/

4. Congruence Statements:
http://www.ck12.org/geometry/Congruence-Statements/

5. Third Angle Theorem:
http://www.ck12.org/geometry/Third-Angle-Theorem/

6. SSS Triangle Congruence:
http://www.ck12.org/geometry/SSS-Triangle-Congruence/

7. SAS Triangle Congruence:
http://www.ck12.org/geometry/SAS-Triangle-Congruence/

8. ASA and AAS Triangle Congruence:
http://www.ck12.org/geometry/ASA-and-AAS-Triangle-Congruence/

9. HL Triangle Congruence:
http://www.ck12.org/geometry/HL-Triangle-Congruence/

10. Isosceles Triangles:
http://www.ck12.org/geometry/Isosceles-Triangles/

11. Equilateral Triangles:
http://www.ck12.org/geometry/Equilateral-Triangles/

Watch the whole series of CK-12's Basic Geometry videos: https://www.youtube.com/playlist?list=PLhWx3LZhlpseSm7selpF8lEq_jtiOqpDX