Use the Creative Grids 22.5 Degree 9.5 inch Triangle Ruler to create Fans, Dresden Plates, etc. up to a finished size of 18 inches. Sew together 16 of these 22.5 degree triangles to create a complete circle; 8 to create a half-circle; or 4 to create a quarter-circle. Total ruler length is 9.5 inches. The ruler slides easily over the fabric until pressure is applied. Then, exclusive gripper holds the fabric in place while cutting, eliminating slipping and miss-cuts!