Without working math problems, cutting triangles, or creating wasted fabric, this ruler helps to make perfect flying geese (4 at a time in 12 different sizes), half square triangles, and quarter square triangles! Simply determine the size you need, and the ruler does the rest! This ruler come highly recommended by eQuilter's Dana Lacy Chapman on our Fabric Passion Forum. Flying Geese x 4 Ruler from Lazy Girl Designs, No math, No waste, No triangles to cut, instructions included. Lazy Girl Designs supports the Susan G. Komen Breast Cancer Foundation with donations for each FGX4 ruler sold.