Use the straight side of this single strip ruler to cut 1-1/2 and 2-1/2 inch strips - or use the pre-cuts that are on the market. Sew these strips together to create a 2-1/2 inch wide strip set. Turn-a-Round the ruler to cut three trapezoids that finish 6 inches. Place two strips of fabric - right sides together - to cut 3 pairs of mirror image trapezoids at one time without wasting any fabric. The key holes in the ruler enable the rotary cutter to cut the sides without damaging the ruler.