Question

If the angle between the plane mirror and the incident ray is ${40}^o$, what are the angles of incidence and reflection ?

Answer 1

$\angle i+{40}^{\circ }={90}^{\circ }$
$\Rightarrow \angle i={50}^{\circ }$
Using laws of reflection , we have :
$\angle i=\angle r={50}^{\circ }$