Draw a square. A second square of the same size slides around the
first always maintaining contact and keeping the same orientation.
How far does the dot travel?
Slide the pieces to move Khun Phaen past all the guards into the position on the right from which he can escape to freedom.
A gallery of beautiful photos of cast ironwork friezes in Australia with a mathematical discussion of the classification of frieze patterns.
This problem is taken from the UKMT Mathematical Challenges.