Question

Refer to the attached picture ​

Answer 1

Angle of Deviation = (Angle of incidence) + (Angle of emergence) - ( Angle of Prism)

This is for a prism, without using any special conditions.

A special condition arises, when you want the minimum angle of Deviation. Then the equation becomes:

Angle of Deviation = 2(Angle of incidence) - ( Angle of Prism).

Hope you understood.

Answer 2

Angle of Deviation (Angle of incidence)+ (Angle of emergence) - (Angle of Prism)

This is for a prism, without using any

special conditions.

A special condition arises, when you want the minimum angle of Deviation. Then the equation becomes:

Angle of Deviation 2(Angle of incidence) - (Angle of Prism).

Thanks