20 faceted (regular) polyhedron is a icosahedron - all facets have equal size. There are variations which have more specific names (where certain facets have irregular shapes) An interesting site to look at is polyhedra.org which shows 6 other variations of 20 faceted polyhedrons: 1. gyroelongated triangular cupola
2. parabiaugmented dodecahedron 3. metabiaugmented dodecahedron
4.triangular hebesphenorotunda
5.gyroelongated triangular cupola
6. elongated triangular orthobicupola
polyhedron
That depends on the kind of polyhedron.There are five kinds of regular polyhedra (all edges of equal length).Tetrahedron (four-sided pyramid) has 6 edgesHexahedron (cube) has 12 edgesOctahedron (eight-sided solid) has 12 edgesDodecahedron (12-sided solid) has 30 edgesIcosahedron (20-sided solid) has 30 edgesIt is also possible to have a polyhedron that is not regular, with almost any number of sides and edges.
icosahedron
In general, any 10-sided polyhedron is called a decahedron. With 10 regular triangles for faces, you may have a pentagonal bipyramid.
a polyhedron (if the shape is 3 dimensional) a polygon if it is a planar shape.
A polyhedron with 20 faces is called an icosahedron.
A 20-sided polyhedron is an icosahedron. A 20-sided polygon is an icosagon.
A 20-sided polyhedron is called an icosahedron. It has 20 equilateral triangle faces, 30 edges, and 12 vertices. It is a regular convex polyhedron with rotational symmetry.
Icos- Icosagon - 20 sided polygon Icosahedron - 20-faced polyhedron
icosahedron (its a 20 sided trinagular faced polyhedron)
an icosahedron (icosagon) is a regular polyhedron with 20 identical equilateral triangular faces
A 120-sided polyhedron is a hecatonicosahedron.
nonahedron
dodecahedron
Tetrahedron, Hexahedron(cube), Octahedron, Dodecahedron, and Icosahedron
A many sided planar figure is a polygon. A many sided solid is a polyhedron.
An octahedron, which looks like 2 pyramids glued bottom to bottom.