Linked from
The 8 pages that link to Angle of incidence, each with the reason it gives.
RefractionRelated: It is the incoming geometric quantity used to determine the refracted angle.
AngleRelated: Optics and mechanics use it to describe how something meets a surface.
Snell's lawRelated: It is one of the two angles whose sines Snell's law relates.
Specular reflectionRelated: Its value determines the reflected ray's direction.
Law of reflectionRelated: It is one of the two angles the law equates.
Turbine bladeRelated: Incorrect incidence can cause separation and reduce blade performance.