Answer:

The angle between the incident ray and the mirror is 40°.

Now, at the point of incidence on the mirror imagine a perpendicular line to the surface of the mirror. This line is referred to as normal. The angle between the incident ray and the normal is called the angle of incidence. This ray after being incident on mirror will get reflected.

There is a law in physics called law of refection. This law states that the angle of reflection is equal to angle of incidence.

So first we must figure out the angle of incidence.

Angle of incidence, i = 90° - 40° = 50°

The angle of reflection, r = 50°

The total angle through which the incident ray turns

= 50° + 50° = 100°

Hope It Helps You.