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.
More recently mathematics has defined a polyhedron as a set in real affine (or Euclidean) space of any dimensional n that has flat sides. It could be defined as the union of a finite number of convex polyhedra, where a convex polyhedron is any set that is the intersection of a finite number of half-spaces.