The pattern of symmetry 2*22
The drawing illustrates the symmetry of a pattern of type 2*22, by putting in evidence the parallelogram of the translations, the axes of reflection (the double lines), the axes of glide reflection (the sketched lines) and the centres of rotation of order 2. Here we can see an example of a pattern characterized by this scheme and this module.
© Angelo Gavezzotti
disegno di Angelo Gavezzotti
The image belongs to the sections...:
The schemes for the 17 wallpaper patterns (Symmetry)
(2D geometry)
Further information:
http://www.iucr.org/iucr-top/comm/cteach/pamphlets/21/sup/