Question

what is the measure of ∠4? a 138° b 52° c 42° d 48°

Explanation:

Step1: Identify vertical - angle relationship

The angle with measure $138^{\circ}$ and $\angle1$ are vertical angles. So, $\angle1 = 138^{\circ}$.

Step2: Identify corresponding - angle relationship

$\angle1$ and $\angle4$ are corresponding angles. When two parallel lines are cut by a transversal, corresponding angles are congruent.

Answer:

A. $138^{\circ}$