Closed shapes with more than three sides and angles can either be convex, concave, regular or irregular polygons. A regular (or simple) polygon is a shape with equal angles and multiple sides with ...

If the appropriate processes are used, wood can be curved and remain in the desired shape - and for this, there is a number of known techniques which Australian company, Sculptform, has perfected.

Optical Surfaces Ltd. is a leading international supplier of concave and convex spherical mirrors made to your exact specification. A spherical mirror is a mirror which has the shape of a piece cut ...

The positive curvature is convex rather than concave ... is described as being open and negatively curved, like the concave shape of a saddle, and quite possibly infinite in extent.

In a ray diagram, a concave lens is drawn as a vertical line with inward facing arrows to indicate the shape of the lens.