Hello Aspirant,

The angle of incidence is tha angle made by the incident ray and the normal. When a ray falls on the mirror normally, it is reflected back through the dame path. Hence incident ray and normal lie on the same path making the angle of incidence zero.

Hi

Angle of incidence:- it is the angle between the incident ray and the normal

Also,

Angle of reflection :- it is the angle between reflected ray and the normal

Normal :- it is a perpendicular line to the surface at which reflection takes place at the point of incidence.

Thank you