The angle of reflection measures the angle at which reflected light bounces off a surface.
- The angle of reflection is measured between a ray of light which has been reflected off a surface and an imaginary line called the normal.
- See this diagram for an explanation: Reflection of a ray of light
- In optics, the normal is a line drawn on a ray diagram perpendicular to, so at a right angle to (900), the boundary between two media.
- If the boundary between the media is curved then the normal is drawn perpendicular to the boundary.