Question

which angles are vertical to each other? ∠1 and ∠9 ∠3 and ∠9 ∠1 and ∠3 ∠12 and ∠5

Explanation:

Step1: Recall vertical - angle definition

Vertical angles are formed when two lines intersect. They are opposite each other and are equal in measure.

Step2: Analyze each option

• For ∠1 and ∠9: They are not formed by the intersection of the same two - line pairs, so they are not vertical angles.
• For ∠3 and ∠9: They are not formed by the intersection of the same two - line pairs, so they are not vertical angles.
• For ∠1 and ∠3: They are vertical angles as they are formed by the intersection of two lines and are opposite each other.
• For ∠12 and ∠5: They are not formed by the intersection of the same two - line pairs, so they are not vertical angles.

Answer:

∠1 and ∠3