With the help of a diagram show double concave and double convex lens and how will you identify both of them by touch

"A double concave lens is the one which has two concave surfaces. Now concave surfaces are the ones which are curved inwards. So, a double concave lens will have two inward curved surfaces. The following diagram shows the double concave lens. (Provide the concave lens image which I have attached)

Similarly, a double convex lens is the one which has two convex surfaces. Now convex surfaces are the ones which are curved outwards. So, a double convex lens will have two outward curved surfaces. The following diagram shows the double convex lens. (Provide convex lens image)

Identifying by touch: When you touch the lens and you feel that the surface that you are touching is bulging or curving outwards then that lens will be a double convex lens. If you are touching the surface and you feel that there is a dent or a curve which is inwards then the lens is a concave lens.