Question

Use the vertical angles theorem to name a pair of congruent angles

Answer 1

If we have two parallel line cut by a transversal such that the number of the angles are ordered in this manner:
1 | 2
3 | 4
5 | 6
7 | 8
The following the pair of vertical angles
∠1 and ∠4
∠2 and ∠3
∠5 and ∠6
∠7 and ∠8