Question

If the angle between the incident ray and the reflected ray is 90°, what are the values of the angle of incidence and angle of reflection?​

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.

Answer 2

Given,

The angle between the incident ray and the reflected ray is 90°.

To Find,

The values of the angle of incidence and angle of reflection.

Solution,

We know that the angle between the incident ray and the reflected ray is 90° and that the angle of incidence and angle of reflection is formed by the normal.

→ According to the laws of reflection, we know that angle of incidence is equal to angle of reflection. [ ∠i = ∠r ]

→ So, in this case too, the angles would be equal.

→ Therefore, the measure of ∠i and ∠r is 90/2 = 45° each.

LAWS OF REFLECTION

→ The angle of incidence is always equal to the angle of reflection.  [ ∠i = ∠r ]

→ The incident ray and the reflected ray lie on the opposite sides of the normal.

→ The incident ray, the reflected ray and the normal- all lie on the same plane.