Question

Which of the following is the best definition of vertical angles?

Answer 1

Step-by-step explanation:

Very quick and effortless example of vertical angles in the attached image. When 2 straight lines intersect, the 2 angles opposite each other at that point are vertical angles, and they are always congruent.

I'd say it's the 3rd option:

"Vertical angles are a pair of non-adjacent angles formed by two intersecting lines."

but any of the first three could be technically true really. Adjacent angles are 2 angles that share a side, and vertical angles cannot share one.