## Complementary and Supplementary Angles

Two or more angles are called *complementary* angles when together they add up to 90°

In the example above ∠ADB and ∠BDC are complementary since together they add up to 90°.

Of course ∠ADC = 90°

Two or more angles are called *supplementary* when they add up to 180°

In the example above ∠x and ∠y are supplementary since together they add up to 180°

How do we know how to add up an angle

the way my old teacher showed me was u have the degrees of the angle, so u just subtract a number from that and add an number to it and if it adds up right, now not all the time will it work but for the most it help me.

Can you send me an example on how to plug in the angles? Thanks