Question

how can you distinguish between plain mirror ,a convex mirror ,and concave mirror without touching them

Answer 1

Walk towards the mirrors.

If The image is lateral and erect and as same size of the object then it is plane mirror.

If the image size is larger that is if it is magnified while u go closer then it is a concave mirror.

If the image size is smaller or diminished then it is a convex mirror.The image will be erect and virtual.

Answer 2

When you look into the mirror,
☆When the image formed is of the same size then it is a plane mirror.
☆When the image is enlarged then it is a concave mirror.
☆When the image is in a diminished size then it is a convex mirror.

HOPE IT HELPS YOU... ☺☺☺☺