Recall that acute angles are angles that measure less than 90°, obtuse angles measure more than 90°, and right angles measure exactly 90°.

Complementary angles are two angles that add up to 90°.
For example, a 30° angle and a 60° angle are complementary because 30°+ 60° = 90°.

Supplementary angles are angles that add up to 180°.
For example, 110° and 70° are supplementary angles because 110° + 70° = 180°.