Question

What is the angle of incidence of a ray of light if the reflected ray is at an angle of ${90}^{\circ }$ to the incidence ray?

Answer 1

If the angle between the incident ray and reflected ray is 90°, the angle of reflection is half of 90° i.e., 45°. Always, the angle of incidence = the angle of reflection. This means that the angle which the normal makes with the incident ray is the same as the angle which the normal makes with the reflected ray.