Answer:
alternate interior angles
Explanation:
We are looking at angles <3 and <6
which are on opposite sides of a transversal (line crossing through 2 parallel lines)
meaning that those 2 angles are congruent and are alternate interior angles are they are on the inside of this figure.
*Can we see the answer choices? I'm not sure what they are, meaning I cannot fully help you*
Hope this helps a little! :)