Some terms related to prism are:
- Angle of deviation (∠ẟ): The difference in the initial and final direction of propagation of light rays is known as the angle of deviation.
- Angle of incidence (∠i): The angle which an incident ray makes with a perpendicular to the surface at the point of incidence.
- Angle of emergence (∠e): The angle of emergence is the angle of the light ray coming out of a medium with the perpendicular to the surface at the point of emergence.
- Prism angle (∠A): The angle between two surfaces of a prism is known as prism angle.
- Refracted angle (∠r): The angle between a refracted ray and the normal drawn at the point of incidence to the interface at which refraction occurs.