Complementary anglesTwo angles are said to be complementary if their sum is 90o. This makes them add up to a right angle. 
In a right triangle,
the 2 angles other than the right angle are
complementary because they add up to 90 degrees.
(All the angles of a triangle add up to 180o). Here's a problem for you: What is the measure of the missing angle in this right triangle? _______ degrees The missing angle (?) and the 45 degree angle are complementary. |