Two plane mirrors makes an angle of `120^(@)` with each other. The distance between the two images of a point source formed in them is 20 cm . Determine the distance from the light source of the point where the mirrors touch, the light source lies on the bisector of the angle formed by the mirrors.

Answer

`11.5 cm =(20)/(sqrt(3))`

Explanation

`Ol_(1)I_(2)` is equilateral triangle `rArr 2d sin 60^(@)=20 rArr d=(20)/(sqrt3) cm`.