Question

in this figure, ab∥cd and m∠1 = 110°. what is m∠5?

Explanation:

Step1: Identify vertical - angle relationship

$\angle1$ and $\angle3$ are vertical angles. So, $m\angle3=m\angle1 = 110^{\circ}$.

Step2: Identify corresponding - angle relationship

Since $AB\parallel CD$, $\angle3$ and $\angle5$ are corresponding angles. Corresponding angles formed by parallel lines and a transversal are congruent. So, $m\angle5=m\angle3$.

Answer:

$110^{\circ}$