The icosahedron (from Greek eikosáedron = twenty-sided) is a convex polyhedron (polyhedron) bounded by congruent equilateral triangles, with five faces meeting in each corner. The icosahedron is one of the five Platonic solids with 20 congruent equilateral triangles as side faces, 30 edges of equal length and 12 corners, where five side faces meet in each corner.