Question

How will you distinguish between a plane mirror, a concave mirror and a convex mirror without touching them?

Answer 1

You can distinguish between a plane mirror, a concave mirror, and a convex mirror without touching them. When you look into these mirrors by bringing your face close to each mirror, they will produce an image of your face of different types.
A plane mirror will produce an image of the same size as your face.
A concave mirror will produce a magnified image of your face.
A convex mirror will produce a Diminished image of your face.