The pattern of symmetry ××
The drawing illustrates the symmetry of a pattern of type ××, by putting in evidence the parallelogram of the translations and the axes of glide reflection (the sketched lines); there are no axes of reflection. 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/
