Border Order - 2
The next three possibiliites for the borders are given in this picture:
(5) a horizontal mirror reflection, A vertical mirror and a glide (reflection in
the horizontal plane followed by a translational movement along the border), and,
(7) vertical and horizontal mirrors (this automatically creates a a80 deg rotation).
These seven and only seven possibilities are called frieze groups. Depending upon
the response, I will give more explanations if necessary.
Regards! - mOhana