Well, considering that those are vertical angles, they must equal 180 degrees in total, which means that each angle is congruent to another. So, since Willow Blvd. intersects Main St., we know that angle 1 = 71 degrees. Now, we must figure out what x could equal.
It's as simple as subtracting 71 from 180, which would equal 9 degrees. The original equation and steps would look like this:
71 + x = 180
180 - 71 = x
9 = x
x = 9
I really do hope this helped you.