â¢ Egyptian Hieroglyphs keyboard (more than 5000) â¢ Egyptian keyboard (Latin alphabet) for transliteration â¢ WikiHiero: online keyboard to type the Hieroglyphs (in several images) â¢ EgyptianHieroglyphs: Middle Egyptian lessons â¢ Gardiner's sign list â¢ Hieroglyphs lessons by Jacques Kinnaer â¢ Friesian school: pronunciation of the Egyptian language â¢ Hieroglyphs classified by category (Gardiner's sign list) â¢ Hieroglyphs classified by family, in colour (Gardiner list) â¢ Projet Rosette: hieroglyphs classified by family (Gardiner list) or transliteration
In elementary geometry, a polyhedron (plural polyhedra or polyhedrons) is a solid in three dimensions with flat polygonal faces, straight edges and sharp corners or vertices. The word polyhedron comes from the Classical Greek ÏÎ¿Î»ÏÎµÎ´ÏÎ¿Î½, as poly- (stem of ÏÎ¿Î»ÏÏ, many) + -hedron (form of á¼Î´ÏÎ±, base or seat).olyhedra with congruent regular faces of six or more sides are all non-convex, because the vertex of three regular hexagons defines a plane. The total number of convex polyhedra with equal regular faces is thus ten, comprising the five Platonic solids and the five non-uniform deltahedra.
Some other polygons, which are not faces, are also important for polyhedra and tessellations. These include Petrie polygons, vertex figures and facets (flat polygons formed by coplanar vertices which do not lie in the same face of the polyhedron).