Question

in the figure, (mangle7 = 100^{circ}). find the measure of (angle9).

Explanation:

Step1: Identify angle - relationship

$\angle7$ and $\angle9$ are corresponding angles. When two parallel lines are cut by a transversal, corresponding angles are congruent.

Step2: Determine the measure of $\angle9$

Since $m\angle7 = 100^{\circ}$ and $\angle7\cong\angle9$, then $m\angle9=100^{\circ}$.

Answer:

$100^{\circ}$