Question

which angles are congruent to each other?
options: ∠11 and ∠9, ∠6 and ∠7, ∠5 and ∠1, ∠6 and ∠10

Explanation:

Step1: Recall congruent angle rules

Congruent angles have equal measure; vertical angles, corresponding angles, alternate interior/exterior angles are congruent.

Step2: Analyze each option

• $\angle11$ and $\angle9$: Adjacent supplementary angles, not congruent.
• $\angle6$ and $\angle7$: Adjacent supplementary angles, not congruent.
• $\angle5$ and $\angle1$: Alternate interior angles, congruent.
• $\angle6$ and $\angle10$: No congruent angle relationship, not congruent.

Answer:

$\angle5$ and $\angle1$