angle of incidence vs incidence angle

angle of incidence and incidence angle both are nouns.

Word	Noun	Adjective	Verb	Adverb
angle of incidence	Yes	No	No	No
incidence angle	Yes	No	No	No

As nouns, angle of incidence and incidence angle are synonyms defined as:

angle of incidence and incidence angle: the angle that a line makes with a line perpendicular to the surface at the point of incidence

angle of incidence (noun)	incidence angle (noun)
the angle that a line makes with a line perpendicular to the surface at the point of incidence	the angle that a line makes with a line perpendicular to the surface at the point of incidence