Question

which angles are vertical to each other?
∠1 and ∠15
∠16 and ∠13
∠1 and ∠7
∠15 and ∠13

Explanation:

Step1: Recall vertical angles definition

Vertical angles are opposite angles formed by two intersecting lines.

Step2: Analyze each option

• For $\angle1$ and $\angle15$: Not formed by two intersecting lines as vertical angles.
• For $\angle16$ and $\angle13$: Not vertical angles.
• For $\angle1$ and $\angle7$: $\angle1=\angle3$ (vertical angles), $\angle3=\angle7$ (corresponding angles), but they are not vertical angles.
• For $\angle15$ and $\angle13$: They are vertical angles as they are opposite angles formed by two intersecting lines.

Answer:

$\angle15$ and $\angle13$