Question

how do we know 120° is supplementary to 60°

Answer 1

If the sum of the measures of two angles is 180° , then the angles are supplementary. Simplify. To isolate a , divide both sides of the equation by 3 . So, the measures of the two supplementary angles are 60° and 120° .

Answer 2

Answer:

see below

Step-by-step explanation:

Supplementary angles are two angles that add to 180

120+60 = 180

The two angles are supplementary