The Law of Reflection

While a ray of light strikes a plane mirror and the light ray reflects off the mirror. Reflection includes a change within direction of the light ray. The convention used to express the direction of a light ray is to denote the angle that the light ray creates along with a normal line drawn to the surface of the mirror. The angle of incidence is the angle among this general line and the incident ray; the angle of reflection is the angle among this common line and the reflected ray. According to the law of reflection, the angle of incidence equals the angle of reflection. These concepts are described within the animation below.