A ray of light is incident on a mirror surface at $60°$.The angle of reflection will be

The angle of incidence is the angle between the incident ray, and the normal angle of reflection is the angle between the normal and the angle of reflection. Normal is the perpendicular drawn to the surface of the mirror.

The given ray is falling on the mirror at  ${60}^{°}$ angle, therefore,

$\alpha =60°$

$\alpha + i=90°$
 

$i=90°-60° = 30°$

According to the law of reflection, the angle of incidence is always equal to the angle of reflection. 

$\therefore r=30°$

The angle of reflection will be$30°$.