The Third Angle Theorem: Lesson (Geometry Concepts)

Discover more at www.ck12.org: http://www.ck12.org/geometry/Third-Angle-Theorem/.

Here you'll learn the Third Angle Theorem and how to use it to determine information about two triangles with two pairs of angles that are congruent.

This video gives more detail about the mathematical principles presented in The Third Angle Theorem.

This is part of CK-12’s 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 Geometry videos: https://www.youtube.com/playlist?list=PLhWx3LZhlpsfZglz0JcMu7AMqcROsISuG