Question

Oak Street and Elm Street run parallel to each other. When Main Street intersects them, it forms exterior ∠8, measuring 60°. What is the measure of ∠2?

Answer 1

Angles 8 and 2 are alternate exterior angles, meaning they are on the same side of the transversal that runs through it but are on the outside.

Alternate exterior angles are supplementary, which means they both have a sum of 180°.

So if you were to find the supplement of 60°, it would be 120°.

This is because;

x + 60 = 180

-60 -60

x = 120, so ∠2 = 120°