Question

1. if (mangle8 = 80^{circ}), then (mangle7=?) a. (72^{circ}) b. (80^{circ}) c. (100^{circ}) d. (108^{circ})

Explanation:

Step1: Identify angle - relationship

$\angle8$ and $\angle7$ are supplementary angles.

Step2: Use supplementary - angle property

Supplementary angles add up to $180^{\circ}$. So $m\angle7=180^{\circ}-m\angle8$.

Step3: Substitute the value of $m\angle8$

Given $m\angle8 = 80^{\circ}$, then $m\angle7=180^{\circ}-80^{\circ}=100^{\circ}$.

Answer:

C. $100^{\circ}$