When I went to Jenny on the Road, she showed us how to turn a Pinwheel (4 half triangles) into many other blocks. Problem was she uses precuts of 5" or 10".... both of which turn out too small for our 12.5. Thus I practiced with some of my BOOM material.
Method, I cut 2 11" blocks. Put right sides together and sewed around the 4 edges (making a box). Then I cut diagonal making an X cut. Pressed open and sewed them together to make a pinwheel (approx 14" block) . Pressed. I then cut 2 equally spaced horizonal and vertical cuts ( basically like a tick-tack-toe board # ). This gave me 9 boxes. Now the fun part. You turn and rearrange the boxes to form new blocks. See my results : ) Finished block turns out to be around 13". Thus, I trimed down to 12.5.
The light blue/green and white is my block to go with my Boom. The others are Mona's (purple/green) and Traveling Grams (butterflies) . Ladies I hope you like them. They were fun to play with.