| Dictionary, Encyclopedia and Thesaurus - The Free Dictionary 1,729,458,925 visitors served. |
|
Dictionary/ thesaurus | Medical dictionary | Legal dictionary | Financial dictionary | Acronyms | Idioms | Encyclopedia | Wikipedia encyclopedia | ? |
polyhedron |
Also found in: Dictionary/thesaurus, Medical, Wikipedia, Hutchinson | 0.02 sec. |
|
polyhedron (pŏl'ēhē`drən), closed solid bounded by plane faces; each face of a polyhedron is a polygon polygon, closed plane figure bounded by straight line segments as sides. A polygon is convex if any two points inside the polygon can be connected by a line segment that does not intersect any side. If a side is intersected, the polygon is called concave. ..... Click the link for more information. . A cube is a polyhedron bounded by six polygons (in this case squares) meeting at right angles. Although regular polygons are possible for any number of sides, there are only five possible regular polyhedrons, having congruent faces, each a regular polygon and meeting at equal angles. The five regular polyhedrons are also known as the Platonic solids, although they were known to the Greeks before the time of Plato. They are the tetrahedron, bounded by four equilateral triangles; the hexahedron, or cube cube, in geometry, regular solid bounded by six equal squares. All adjacent faces of a cube are perpendicular to each other; any one face of a cube may be its base. The dimensions of a cube are the lengths of the three edges which meet at any vertex. ..... Click the link for more information. , bounded by six squares; the octahedron, bounded by eight equilateral triangles; the dodecahedron, bounded by twelve regular pentagons; and the icosahedron, bounded by twenty equilateral triangles. The 18th-century Swiss mathematician Leonhard Euler showed that for any simple polyhedron, i.e., a polyhedron containing no holes, the sum of the number of vertices V and the number of faces F is equal to the number of edges E plus 2, or V+F=E+2. polyhedronIn 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. polyhedronA six- or more-sided object. A group of connected polygons. polyhedron a solid figure consisting of four or more plane faces (all polygons), pairs of which meet along an edge, three or more edges meeting at a vertex. In a regular polyhedron all the faces are identical regular polygons making equal angles with each other. Specific polyhedrons are named according to the number of faces, such as tetrahedron, icosahedron, etc. polyhedron [¦päl·i¦hē·drən] (mathematics) A solid bounded by planar polygons. The set of points that belong to the simplexes of a simplicial complex. How to thank TFD for its existence? Tell a friend about us, add a link to this page, add the site to iGoogle, or visit webmaster's page for free fun content. |
|
| ? Mentioned in | ? References in periodicals archive | ||
|---|---|---|---|
| They've also used spidrons to construct many innovative three-dimensional forms--rings, nests, linkages, labyrinths, polyhedrons, and more. With its 12-sided dodecahedral design, it has the ideal structure to create this size of multi-sided polyhedron sphere. But I had one of these polyhedrons that I had built in New York, and I said that I could make it into a tower. |
| Encyclopedia |
| Free Tools: |
For surfers:
Free toolbar & extensions |
Word of the Day |
Help
For webmasters: Free content | Linking | Lookup box | Double-click lookup | Partner with us |
|---|