I had to go look that up. On that sheet, when you see the dotted lines it indicates sew. I used paper foundations for the flying geese and then for the center square, I drew that exact line on the back of the fabric, sewed it, trimmed & pressed open. I used the same method as Lisa for the HST's. If you need a foundation for the flying geese, PM me your email address and I will send you something that is print-able.