Question

What is the angle of incidence of a ray if the reflected ray is at an angle of 90° to the incident ray..?

Answer 1

$\textbf{ sᴏʟᴜᴛɪᴏɴ :-}$

$\implies\angle i = \angle r$

$\implies \angle i \: + \: \angle r = 90 \degree$

$\implies \angle i \: + \: \angle i = 90 \degree$

$\implies 2 \angle i = 90 \degree$

$\implies \angle i = \frac{90 \degree}{2} = 45 \degree$

$the \: angle \: of \: incidence \: is \: 45 \degree$

Answer 2

The angle of incidence ray will be 45°.