The law of reflection states that when a ray of light reflects off a surface, the angle of incidence (the angle at which the light strikes the surface) is equal to the angle of reflection (the angle at which the light reflects off the surface). This law applies to all types of light and all types of surfaces, including plane mirrors. When light reflects off a plane mirror, it is reflected at the same angle as it hit the mirror, and the reflected light travels in a different direction. This is known as specular reflection.