Question

select the correct answer.
mary is standing at a place such that she makes an angle of 42° to the right of the normal of a mirror. where should marys mom stand so that she can best see marys reflection in the mirror?

a. at an angle 84° to the right of the normal
b. directly behind mary
c. at an angle of 42° to the left of the normal
d. at an angle 90° with the normal

Explanation:

To see the reflection best, the law of reflection (angle of incidence = angle of reflection) applies. Mary is at \(42^\circ\) right of normal (incidence angle). The observer (mom) should be at the reflection angle, which is \(42^\circ\) left of normal (since reflection angle equals incidence angle, and on the opposite side of the normal from the incident ray). Option A is incorrect (angle is double, not the reflection angle). Option B is incorrect (behind Mary doesn’t relate to reflection angles). Option D is incorrect (\(90^\circ\) doesn’t match the reflection angle. Only option C matches the law of reflection.

Answer:

C. at an angle of \(42^\circ\) to the left of the normal