Which rules would result in a triangle a being congruent to or not congruent to b? (see attachment)

Tori examined the pattern of exponents in the table. based on the pattern, which statements are true? check all that apply.

International calls require the use of a country code. many country codes a 3-digit numbers. country codes do not begin with a 0 or 1. there are no restrictions on the second and third digits. how many different 3-digit country codes are possible?

Consider the proof. given: segment ab is parallel to line de. prove: what is the missing statement in step 5?