Question

⦟13 and ⦟15 are congruent, or supplementary?

Answer 1

Angle 13 and angle 15 are congruent

Answer 2

∠13 ≅ ∠15

Explanation:

By the vertical angles theorem, we can see that angles 13 and 15 are congruent.

But, what is vertical angles theorem?

The vertical angles theorem is when two angles are congruent if they are formed by two straight lines intersecting. Vertical angles must share the same vertex and are on opposite sides of the vertex in which the lines intersect.

We can see that angles 13 and 15 intersect each other, share the same vertex, and are on opposite sides so we can say that they are congruent by the vertical angles theorem.