Question

Two plane mirrors are inclined at an angle of `60^@` as shown in Figure. A ray of light parallel to `M_(1)` strikes `M_(2)`. At what angle will the ray finally emerge?

Answer 1

The angle that the ray makes after each reflection is clearly labeled in the following figure. It is clear that final ray makes an angle of `60^@` with the horizontal, or in other words it emerges parallel to mirror 1.