Question

(a) an angle measures 28°. what is the measure of its complement? (b) an angle measures 129°. what is the measure of its supplement?

Explanation:

Step1: Recall complement - angle formula

Complementary angles add up to 90°. Let the given angle be $\theta = 28^{\circ}$. The measure of its complement $\alpha$ is given by $\alpha=90^{\circ}-\theta$.

Step2: Calculate the complement

$\alpha = 90^{\circ}-28^{\circ}=62^{\circ}$

Step3: Recall supplement - angle formula

Supplementary angles add up to 180°. Let the given angle be $\beta = 129^{\circ}$. The measure of its supplement $\gamma$ is given by $\gamma = 180^{\circ}-\beta$.

Step4: Calculate the supplement

$\gamma=180^{\circ}-129^{\circ}=51^{\circ}$

Answer:

Measure of the complement: $62^{\circ}$
Measure of the supplement: $51^{\circ}$