(plural: polyhedra) Any 3-dimensional geometrical figure with many sides Pyramids, cubes, and geodesic domes are all polyhedra From the Greek roots poly (meaning many) and hedron (meaning side)
Three-dimensional object bound by polygons The polygons, or faces, are typically planar and finite, and meet with exactly two at each edge If more than two faces meet at each edge, the model is sometimes called degenerate
(pl polyhedra) A set that equals the intersection of a finite number of halfspaces This is generally written as {x: Ax <= b}, where the representation (A,b) is not unique It is often useful to separate the implied equalities: {x: Ax <= b, Ex = c}, so that the relative interior is {x: Ax < b, Ex = c} The system, {Ax <= b, Ex = c}, is a prime representation if it is irredundant, and it is minimal if it is irredundant and contains no implied equality A polyhedron is degenerate if it contains an extreme point that is the intersection of more than n halfspaces (where n is the dimension of the polyhedron) An example is the pyramid (you need a graphics browser to see it, in which case you might also want to see David Chasey's collection of acryllic polyhedra and/or 3D views of virtual polyhedra)
A solid formed by polygons that enclose a single region of space The flat polygonal surfaces of a polyhedron are called its faces A segment where two faces of a polyhedron intersect is an edge A point of intersection of three or more edges is a vertex (Lesson 11 1 )
1 A region in Euclidean space which consists of flat facets with flat edges More technically, a polyhedron must locally be a cone over a lower-dimensional polyhedron It is sometimes but not always implicitly assumed that a polyhedron is a manifold, a topological sphere or ball, or a convex set 2 An abstract space with properties analogous to that of a polyhedron, such as a simplicial complex -----
A solid figure bounded by plane polygonal faces The point at which three or more faces intersect on a polyhedron is called a vertex, and a line along which two faces intersect is called an edge In a regular polyhedron, all the faces are congruent regular polygons There are only five regular polyhedra: tetrahedron, octahedron, cube, icosahedron, and dodecahedron (see "Platonic Polyhedra" above)
Most basicly its a solid cube which is convex A polyhedron consists of at least 4 faces so they create a 3-sided pyramid, and up to several hundred faces which probably will be something like a sphere Synonyms that are commonly used for polyhedrons are; brush, cube
a solid shape with many sides (polyedron, from hedra ). In Euclidean geometry, a three-dimensional object composed of a finite number of polygonal surfaces (faces). Technically, a polyhedron is the boundary between the interior and exterior of a solid. In general, polyhedrons are named according to number of faces. A tetrahedron has four faces, a pentahedron five, and so on; a cube is a six-sided regular polyhedron (hexahedron) whose faces are squares. The faces meet at line segments called edges, which meet at points called vertices. See also Platonic solid; Euler's formula