Creative Grids 15 degree Ruler
Sew together 24 of these 15 degree triangles to create a complete circle; 12 to create a half-circle; or 6 to create a quarter-circle. Create Fans, Dresden Plates, etc. up to a finished size of 48 inches. Total ruler length is 24-1/2 inches. Use the vertical lines to fussy cut stripes or cut half triangles (the 1/4 inch seam allowance is marked).