Question

two angles are supplementary if the sum of their measures is 180. angles A and B are supplementary. if the measure of angle A is 78 write and solve an addition equation to find the measure of angle B.

Answer 1

78° + B = 180°

B = 102°

Explanation:

"Supplementary" means angle A and B added together are 180°.

We know A is 78, but we don't know B

Write an equation:

A + B = 180°

Fill in what we know.

78° + B = 180° this is the equation the question is asking for.

To solve, subtract 78 from both sides of the equation.

B = 102°