Reflection

When a wave reflects from a surface:

• The angle of incidence equals the angle of reflection.
• Both angles are measured from the normal (the line perpendicular to the surface at the point of incidence).
• The frequency, wavelength and speed of the wave remain unchanged.

Smooth surfaces produce regular (specular) reflection, giving clear images. Rough surfaces produce diffuse reflection, scattering light in many directions.

All types of waves can be reflected: light, sound, water waves, radio waves.