Not all groups of eubacteria have peptidoglycan, so all eubacteria may be classified as either Gram-positive (able to bind Gram's stain) or Gram-negative (unable to bind Gram's stain).
A portable DVD player is in the shape of a rectangular prism. A soccer ball is in the shape of a truncated icosahedron. These shapes are all examples of polyhedra. A three-dimensional shape whose faces are polygons is known as a polyhedron. This term comes from the Greek words poly, which means many, and hedron, which means face.. So, quite literally, a polyhedron is a three-dimensional object with many faces.
A dodecahedron is any polyhedron with twelve faces, but usually a regular dodecahedron is meant: a Platonic solid composed of twelve regular pentagonal faces, with three meeting at each vertex. It has twenty (20) vertices and thirty (30) edges. Its dual polyhedron is the icosahedron. If one were to make every one of the Platonic solids with edges of the same length, the dodecahedron would be the largest.