Question

Fig. shows an incident ray $AO$ and the normal $ON$ on a plane mirror. The angle which the incident ray $AO$ makes with the mirror is ${30}^{\circ }$. Find the angle of incidence.

Answer 1

Angle of incidence is the angle between incident ray $\left(AO\right)$ and normal of the plane $\left(ON\right)$ at the point of incident.

Here,
Angle of incidence,
$\angle i={90}^{\circ }-{30}^{\circ }={60}^{\circ }$
(using basic geometry)