How does the angle of incidence compare with the angle of refraction?

Answer 1

The angle of incidence, i, is the angle that the incident ray makes with the normal line. The angle of refraction, r, on the other hand, is the angle that the refracted ray makes with the normal line. The relationship between them is

a sine i = b sine r

where a and b are the constants known as the refractive indices of the respective media. They are more commonly represented as n(subscript 1) and n(subscript 2) but this interface won't let me do subscripts!