Question

which angle is vertical to ∠4?

Explanation:

Step1: Recall vertical - angle definition

Vertical angles are formed when two lines intersect. They are opposite each other and are congruent.

Step2: Identify vertical angle to ∠4

In the given figure, when two lines intersect at the point, ∠4 and ∠1 are opposite each other. So, ∠1 is vertical to ∠4.

Answer:

∠1