Concave is not a shape, it is the term for when two lines meet facing inwards, rather than outwards (outwards is known as convex)
No
yes concave is like a cave
A geometric star shape is concave. A star that is in the sky is convex.
no
Depends on a concave what. There can be infinitely many right angles in concave shape that keeps going in and out before returning to its starting point.
no concave mirror is in shape of concave mirror
No
yes concave is like a cave
A geometric star shape is concave. A star that is in the sky is convex.
A concave circle
no
An arrow can have both concave and convex surfaces, depending in its design.
The sheep's eye is concave, the surface of the shape of the lens are circular.
convex
a figure or shape that curves in not out
concave
A spoon that you have put some food into is a concave shape. It is a cavity. A concave lens is such that it is thicker at the edges than in the middle. Convex is the bottom of the spoon. A convex lens is thicker in the centre than around the edges.