I have always been fascinated by flags with their range of bright colours and designs. These flags at the South Pole would uplift any traveller’s spirits! Flags make a great starting point for the study of symmetry. What reflections or rotations (if any) map the flag onto itself? Some elementary group theory appears here as well. Then there is the square Swiss flag with its centrally placed cross – another story altogether. The rectangular symmetries appear in other places too: the orientations of an envelope or of a rectangular bus pass.
