Question

Two plane mirrors are arranged at right angles to each other as shown in figure. A ray of light is
incident on the horizontal mirror at an angle 'e'. For what value of ethe ray emerges parallel to
the incoming ray after reflection from the vertical mirror?​

Answer 1

For ray A and B to be parallel

2θ+2α=180°

θ+α=90°

andθ=α

soθ=45°