Creative Grids 30 Degree Triangle Quilt Ruler CGRSG1. Sew together twelve triangles to create a complete circle; six to create a half-circle; or three to create a quarter-circle. This tool can be combined with the Creative Grids Circle Savvy ruler to cut pieced arcs which can be incorporated into any circle pattern. Create Fans, Dresden Plates, etc. up to a finished size of 38 inches. Use the vertical lines to fussy cut stripes or cut half triangles (the 1/4 inch seam allowance is marked). Or cut 30; 45; and 60 degree units with the angles marked on the ruler. This triangle may be used as a companion to the Circle Savvy Ruler, Item CHK-CGRSAV1. The ruler comes with fully illustrated step by step instructions or scan the QR Code printed on the ruler to view a video demonstration. 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. Total Size - 10-3/4 inches x 19-1/2 inches. CHK-CGRSG1