I had 20 pinwheel blocks of different sizes. I tried to arrange them on the design wall. Then I looked at math problems of this type, and got some ideas. I computed how to fit together five blocks, two small the same size, two medium different sizes, and one large. This only required basic arithmetic, and I figured out how to fit together about 26 rectangles using the block sizes that I had. I put the numbers into an Excel spreadsheet and then in a very convoluted way I figured out how to put four such rectangles together. It wasn't easy. If I knew how to use my C compiler I could have optimized it better and probably saved a lot of time. I had to trim down most of the pinwheels, but in the end I'm very happy with the result. It's going in the UFO bin because I don't think I have any spare batting, and I have a few other quilts I want to finish. When I finish it I'm going to call it "Friends."