### Home > CCG > Chapter Ch7 > Lesson 7.2.2 > Problem 7-67

7-67.

A light directed from point * *is pointed at a hinged mirror with right angle as shown at right.

If

measures , find the measures of , , , , and . When the light hits the mirror the angle of incidence and angle of reflection are congruent. Therefore

, , , , Why must the arrows at points

andbe parallel?Use the angle measurements found to explain why the arrows at points

andmust be parallel.