Concept in Definition ABC

The term polyhedron is the one used to designate those geometric figures three-dimensional that are composed of several faces or facets. It can be said that the polyhedron is the equivalent of the polygons, the figures flat geometric with many sides but without three-dimensionality. The name of polyhedron comes from the Greek language for which poli means "many" and edro or edron means "faces".

Polyhedra are much more visually striking than a polygon. This has to watch with the fact that they gain three-dimensionality and, therefore, their surface it becomes much more complex. The elements that normally make up a polyhedron are three, some of them equivalent to those of the polygon: the faces, the edges and the vertices. The faces are the blueprints that are formed along the surface of the polyhedron and that can be very numerous depending on the polyhedron in question. Then the edges or lines that delimit the planes between themselves and that can be shared by two planes together continue. Finally, the vertices, as in the polygon, are the point of union of two or more edges as well as of two or more planes.

Polyhedra, as might be expected, are complex figures that can be grouped into two main sets: regular and irregular polyhedra. While the former are characterized by being composed of faces and vertices equal to each other, the irregular ones are a composition of faces and vertices of different size and level, so your final view is much more impressive and messy. Among the first, regular polyhedra, we find, for example, cubes. In the group of irregular polyhedra one of the best known forms is the prism in all its variants as well as also the figures that bear the name "truncated" together with the number of faces they have (for example the Tetrahedron truncated).