Question

In the figure, line L1 is parallel to line L2. If the measure of ∠7 = 42°, what is the measure of ∠3 and why?

A) 42°, alternating interior angles are congruent

B) 42°, corresponding angles are congruent

C) 42°, same side exterior angles are congruent

D) 18°, corresponding angles are supplementary

Answer 1

Answer: Choice B

42°, corresponding angles are congruent

The angles 3 and 7 are in the same bottom left corner (aka southwest corner), which means they are one corresponding pair. Another pair would be angle 1 with angle 5 in the northwest corner. There are two other pairs. Corresponding angles are congruent when we have parallel lines like this.