Question

Draw a figure describing the following.
The reflecting surface of two mirrors make an angle of 90^∘ with each other. If a ray incident of one mirror has an angle of incidents of 30^∘, draw the ray reflected from the second mirror. What will be its angle of reflection?

Answer 1

Let r₂ be the angle of reflection from the second mirror.

From laws of reflection,
$\angle i_1=\angle r_1={30}^{\mathrm{o}}$
Now, in $∆\mathrm{ABC}$,
$$\begin{gathered} \theta ={180}^{\mathrm{o}}-{90}^{\mathrm{o}}-{60}^{\mathrm{o}}={30}^{\mathrm{o}} \\ \Rightarrow i_2={60}^{\mathrm{o}} \\ \mathrm{Hence},r_2={60}^{\mathrm{o}} \end{gathered}$$
The angle of reflection of incident ray is 60^∘.