Question

the measure of an angle is 58.1°. what is the measure of its supplementary angle?

Explanation:

Step1: Recall supplement - angle formula

The sum of an angle and its supplementary angle is 180°. Let the given angle be $\theta = 58.1^{\circ}$ and its supplementary angle be $\alpha$. Then $\theta+\alpha = 180^{\circ}$.

Step2: Solve for the supplementary angle

We can rewrite the formula as $\alpha=180^{\circ}-\theta$. Substitute $\theta = 58.1^{\circ}$ into the formula: $\alpha = 180 - 58.1=121.9^{\circ}$.

Answer:

$121.9^{\circ}$