Suppose that you are a manufacturer of decorative tiles.
You could define an area A and then produce a kit of round tiles of areas A1, A2, ... , some finite number of them. Presumably they would have different colors or patterns.
The user would then lay out an area A on a floor or wall. It could be square, somewhat oblong, or even round. He would then place the tiles anywhere he wants starting with the largest and proceeding in order. The principles of construction guarantee that they would all fit regardless of where he places them. It would not necessarily work if he placed the tiles in a different order.
This novel idea is hereby placed in the public domain.