Sew together 16 of these 22-1/2 degree triangles to create a complete circle; 8 to create a half-circle; or 4 to create a quarter-circle. Create Fans, Dresden Plates, etc. up to a finished size of 18 inches. Total ruler size is 4-1/4 in. x 9-1/2 in. Use the vertical line to fussy cut stripes or cut half triangles (the 1/4 inch seam allowance is marked). Or use the angled lines to create intricate blocks as instructed in companion patterns. <a href="https://youtu.be/KE977FyJP2I" target="_blank">Watch a Creative Grids instructional video.</a> The ruler slides easily over the fabric until pressure is applied. Then, the exclusive gripper holds the fabric in place while cutting, eliminating slipping and miss-cuts!