Question

review the diagram.
ef and gh are parallel.
ef and gh are intersected by line t.
select the angle - pair which are vertical angles

Explanation:

Step1: Recall vertical - angles definition

Vertical angles are opposite angles formed by the intersection of two lines.

Step2: Identify vertical - angle pairs in the diagram

In the given diagram, when lines intersect, ∠1 and ∠3 are vertical angles, and ∠2 and ∠4 are vertical angles.

Answer:

∠1 and ∠3, ∠2 and ∠4