Supplementary and Complementary Angles in a Triangle

Front

What are supplementary angles?

Back

Two angles are supplementary if their measures add up to 180 degrees.

Front

How are supplementary angles related to a triangle?

Back

While individual angles in a triangle are not supplementary, any two angles in a triangle can be considered supplementary when combined with the third angle. For example, if you have angles A and B in triangle ABC, then A + B + C = 180°. Therefore, A + B can be considered supplementary to angle C.

Front

What are complementary angles?

Back

Two angles are complementary if their measures add up to 90 degrees.

Front

How are complementary angles related to a triangle?

Back

Angles in a triangle are not typically complementary in the same way as supplementary angles. However, if you take one angle from a triangle and look at the angles outside the triangle formed by extending one side, then those external angles could be complementary to the angles inside.