Definition: An icosahedron is a three-dimensional geometric shape, a type of polyhedron, that has twenty faces. Each of these faces is an equilateral triangle. It is one of the five Platonic solids, which are convex polyhedra with faces composed of congruent, regular polygons and the same number of faces meeting at each vertex.
Etymology and Origin: The term ‘icosahedron’ comes from Greek, combining ‘eikosi’ (είκοσι), meaning ‘twenty’, and ‘hedron’ (ἕδρα), meaning ‘seat’ or ‘face’. This term was used in ancient Greek mathematics and geometry to describe this specific twenty-faced solid. The study of such shapes can be traced back to the works of early Greek mathematicians, including Plato and Euclid.
