Geometry:

Adding Angles

Suppose that angle A measures a degrees and that angle B measures b degrees. You should know the following definitions:

• Angles A and B are complementary if and only if they add up to a right angle.
  a + b = 90
  
• Angles A and B are supplementary if and only if they add up to a straight line.
  a + b = 180
  
• If angles A and B add up to a full circle, then
  a + b = 360