Or search by topic
Try using a mirror to check your symmetries.
Try keeping the biggest shape fixed in one position, place the rectangle systematically in all possible positions, and see whether the square can be added to make a symmetrical shape.
A gallery of beautiful photos of cast ironwork friezes in Australia with a mathematical discussion of the classification of frieze patterns.
Patterns that repeat in a line are strangely interesting. How many types are there and how do you tell one type from another?
Some local pupils lost a geometric opportunity recently as they surveyed the cars in the car park. Did you know that car tyres, and the wheels that they on, are a rich source of geometry?