Exercise 53 Page 425

We are told that Route 10 runs perpendicular to Interstate 95 and Interstate 295. Let's recall that perpendicular lines intersect to form four right angles. Thus, ∠ 1 and ∠ 2 are the right angles.

Theorem 2.10 states that all right angles are congruent. Using this theorem, we conclude that ∠ 1 and ∠ 2 are congruent angles.