You are given three mirrors of equal size—concave, convex and plane. How will you identify them without touching their surfaces?

Identification of mirror: 

We are given three mirrors. Let's see our faces in each mirror, turn by turn. Initially, keep the face close to the mirror but, slowly move away from the mirror. 

1. If the image formed on the mirror is of the same size as our face but laterally inverted (i.e., left face looks right and vice-versa) for all positions, then it is a plane mirror. 

2. If the image formed is erect and enlarged initially but gets inverted as the face is moved away, then it is a concave mirror. 

3. If the image formed is erect and smaller in size for all positions, then it is a convex mirror.