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 (3D) Tactics Analysis history. The notion of 3D tactics has been developed from the spherical security concept. The 3D tactics model identifies some of the key phenomenon experienced in urban environments. In particular, the 'inherent information deception qualities' found in 'vertical rather than horizontal envelopment'. A key aspect, in urban tactics, is the importance in achieving, what is called 'spherical security', that is, the three-dimensional nature of the urban battle places a premium on all-round security. This requires tactical thinking in three dimensions. 3D tactics are often represented as a cube of space within which the tactical analysis takes place: The 3D tactics