Question

define angle of incidence and angle of reference​

Answer 1

Answer:

In optics, angle of incidence can be defined as the angle between a ray incident on a surface and the line perpendicular to the surface at the point of incidence (called as normal).

In mathematics, the reference angle is defined as the acute angle and it is measuring less than 90 degrees. It is always the smallest angle, and it makes the terminal side of an angle with the x-axis. The reference angle is used for the purpose of the simplification of the calculations in the trigonometric function value at different angles.