Question

the measure of an angle is 102°. what is the measure of its supplementary angle?

Explanation:

Step1: Recall the definition of supplementary angles

Supplementary angles add up to 180°.

Step2: Calculate the supplementary angle

Let the supplementary angle be $x$. We have the equation $x + 102^{\circ}=180^{\circ}$. Then $x=180^{\circ}- 102^{\circ}$.
$x = 78^{\circ}$

Answer:

78