Question

If the light rays in the incident ray originate at 20º from the surface...

Answer 1

Given :

The light rays in the incident ray originate at 20º from the surface.

To Find :

The angle for the incident ray.

Solution :

We know angle of incidence is measured from perpendicular to the surface .

So,

$\theta_i = 90^o - 20^o\\\\\theta_i = 70^o$

Now, we know by law of reflection :

Angle of reflection = Angle of incident

$\theta_r = 70^o$

Therefore, the angle of incident and reflection is 70° each.