This is a very traditional design that is worth experimenting with. It goes well on a nine-patch where the finished block is 9" but it also has great potential with other 9" blocks. When configured as below on the left, the measurement from the outer edge of the 3 squares to opposite 3 squares outer edge is 11 1/2". Remember you will lose 1/2 on each side due to the overlap of the 3 square section so they fit well into a 11 inch block. If you butt the 3 squares against each other making a six square configuration it will fit into 12 inch blocks nicely.