Question

which angle is not congruent to ∠1?

Explanation:

Step1: Identify angle - relationships

When two parallel lines are cut by a transversal, vertical angles are congruent, corresponding angles are congruent, and alternate - interior and alternate - exterior angles are congruent.

Step2: Analyze each angle

∠1 and ∠3 are vertical angles, so ∠1≅∠3. ∠1 and ∠5 are corresponding angles, so ∠1≅∠5. ∠1 and ∠7 are alternate - exterior angles, so ∠1≅∠7. ∠1 and ∠2 are adjacent and supplementary, not congruent.

Answer:

∠2