A concaved shape is one that is curved like the inner surface of a sphere. (Think about something that is cave-like.)
The opposite, a convex surface, is one that is shaped like the outer surface of a sphere.
So the mirror in a telescope has a concaved surface, as does the inside of a bowl and the surface of a crater or valley.
The opposite of convex is concave. Concave shapes have an inward curve, while convex shapes have an outward curve.
plano concave
Concave, because you can connect the corners from the outside.
Concave is a property of [irregular] polygons. A parallelogram cannot be concave.
no concave mirror is in shape of concave mirror
concave=in convex=out
concave
His glasses have a concave lens.
Rectangle
concave
concave
Yes, a triangle is always concave. * * * * * How wrong can you get! A triangle is always convex and NEVER concave.