Two angles that sum to a straight angle -LRB- NUMBER@1 ° -RRB- are called supplementary angles .

A straight angle -LRB- or straight line -RRB- is an angle equal to NUMBER@1 ° . Supplementary angles are two angles with the sum equal to NUMBER@1 ° . Two angles that sum to one right angle -LRB- NUMBER@2 ° -RRB- are called complementary angles . Two angles that sum to one full circle -LRB- NUMBER@3 ° -RRB- are called explementary angles or conjugate angles .
