In the figure shown,how many images of the star will an observer at $O$ see?

The focal length of a plane mirror is:

Two plane mirrors are placed at an angle of $60^\circ$. $A$ horizontal light ray is reflected by the first mirror and then by the second mirror. The total deviation will be ........... $^\circ$.

$A$ ray of light is incident at $50^{\circ}$ on the middle of one of the two mirrors arranged at an angle of $60^{\circ}$ between them. The ray then touches the second mirror,gets reflected back to the first mirror,making an angle of incidence of.........$^{\circ}$

What is reflection of light? Explain the laws of reflection.

$A$ man is $180\,cm$ tall and his eyes are $10\,cm$ below the top of his head. In order to see his entire height from toe to head,he uses a plane mirror kept at a distance of $1\,m$ from him. The minimum length of the plane mirror required is.....$cm$.