Question

the measure of an angle is 173°. what is the measure of its supplementary angle?

Explanation:

Step1: Recall supplementary - angle definition

Two angles are supplementary if their sum is 180°. Let the given angle be $A = 173^{\circ}$ and the supplementary angle be $x$. Then $A + x=180^{\circ}$.

Step2: Solve for the supplementary angle

We can find $x$ by subtracting the given angle from 180°. So $x = 180^{\circ}-173^{\circ}$.
$x = 7^{\circ}$

Answer:

$7$