When light reflects off a smooth surface, what is the angle of reflection?

The angle of reflection is equal to the angle of incidence because this principle is a fundamental law of optics known as the law of reflection. When light rays strike a smooth surface, they reflect off that surface at the same angle at which they arrived. This means that if a light beam hits the surface at a certain angle (the angle of incidence), it will reflect off at the same angle (the angle of reflection), measured from a normal line which is perpendicular to the surface at the point of incidence.

This principle holds true for all smooth surfaces, such as mirrors or calm water, where the reflection produces a clear image. The consistency of the angle of reflection is a key characteristic of how light behaves, and it is crucial for understanding various optical applications and phenomena, such as image formation and the functioning of optical devices.