To explain the law of reflection, let us define some of the terms we are going to use in this part:

Incident Ray is the ray striking the surface.
Reflected Ray is the ray reflected from the surface.
Point of Incidence is the point at which the incident ray strikes the surface.
Normal (N) is a line drawn perpendicular to the surface at a point where the incident ray strikes the surface.
Angle of Incidence (i) is the angle between the incident ray and the normal to the surface.
Angle of Reflection (r) is the angle between the reflected ray and the normal.
The law of reflection is stated as follows:

1. The incident ray, the reflected ray and the normal to the surface lie in the same plane.
2. The angle of incidence is equal to the angle of reflection, i.e., i = r.