# Supplementary and complementary angles

Complementary angles are two angles with a sum of 90°.

Supplementary angles are two angles with a sum of 180°.

C is 90° and S is made up of two C’s, so S must be 180°.

Example 1

40° and 50° are complimentary angles.

Example 2

60° and 30° are complimentary angles.

Example 3

140° and 40° are supplementary angles.

Example 4

110° and 70° are supplementary angles.

Example 5

120° + 60° add up to 180° and so they are supplementary.