The second exercise is due on Sep 15, 2014.
Download a pdf version of the homework.
The second exercise a few aspects of symmetry in patterns. Our patterns are composed of atoms in crystals. This is a two-dimensional analog.
A simple two-dimensional crystal with two atoms arranged in in a p4mm pattern
Patterns in three dimensions, real crystal structures, offer more possibilities, but the principles of identification of symmetry content are well illustrated by this simple example.