Point groups in three dimensions the finite subgroups of SO(3), are: the cyclic groups "C" (the rotation group of a canonical pyramid), the dihedral groups "D" (the rotation group of a uniform prism, or canonical bipyramid), and the rotation groups "T", "O" and "I" of a regular tetrahedron, octahedron/cube and icosahedron/dodecahedron. In particular, the dihedral groups "D", "D" etc. are the rotation groups of plane regular polygons embedded in three-dimensional space, and such a figure may be considered as a degenerate regular prism. Therefore, it is also called a "dihedron" (Greek: solid with two faces), which explains the name "dihedral group". The rotation group of
Three Dimensional E.C. Classics Three Dimensional E.C. Classics Three Dimensional E.C. Classics was a quarterly comic book anthology series published by EC Comics in 1954. It began publication with its Spring 1954 issue and ceased with its March 1954 issue, producing a total of two issues. The stories it contained were "classics" in that they were recyclings of stories that had already appeared in earlier EC comic books. They were "three-dimensional" because they were presented in Anaglyph 3-D. Two 3-D viewers were included with each issue. "Three Dimensional E.C. Classics" was conceived in 1953, when 3-D comic books were enjoying a period of great