Sew together 36 of these 10 degree triangles to create a complete circle; 18 to create a half-circle; or 9 to create a quarter-circle. Create Fans, Dresden Plates, etc. up to a finished size of 31-1/2in. Total ruler length is 16in. The ruler slides easily over the fabric until pressure is applied. Then, our exclusive gripper holds the fabric in place while cutting, eliminating slipping and miss-cuts!