Dr. Mark P. Siegel, DO http://d1ffafozi03i4l.cloudfront.net/img/silhouettes/silhouette-male_w120h160_v1.jpg Visit Healthgrades for information on Dr. Mark P. Siegel, DO.
Opposite of concave . A geometric shape is convex if all its edges point outwards. That is no part of it curves or faces inwards. If a shape is convex, a line segment drawn between any two points on the shape will always lie inside the shape. The figure above is a convex pentagon. No part of it is caved in and any line segment, such as the red one shown, linking two points on it always lies inside the shape. See also Concave definition.
Cubes and pyramids are examples of polyhedra. A polyhedron is said to be convex if its surface (comprising its faces, edges and vertices) does not intersect itself and the line segment joining any two points of the polyhedron is contained in the interior or surface. A polyhedron is a 3-dimensional example of the more general polytope in any number of dimensions.