Question

Two plane mirrors are inclined at an angle of ${60}^o$ with each other. An incident ray hits one of the mirror at an angle of ${80}^o$ with the normal. Its angle of deviation after two reflections is

• A. ${120}^o$
• B. ${240}^o$
• C. $zero$
• D. ${60}^o$

Answer 1

The correct option is A ${120}^o$

$\begin{array}{c}\text{All angles are found using (angle sum of}\Delta \text{) and}(\angle i=\angle r)\\ \text{Amswer is}{120}^{\circ }\text{.}\end{array}$