Question

if the refracting angle of prism is 60 and minimum deviation is 30 the angle of incidence will be

Answer 1

A = 60°
d min = 30°

We know,
d min = i - A
30 = i - 60
i = 90°


I am not sure if the formula is correct.

Answer 2

Given,
Angle of deviation=30 and
Angle of prism,A=60
We know,
Angle of deviation(minimum)=2i-A
30=2i-60
2i=60+30
i=90/2=45
Therefore angle of incidence=45°