As a former math teacher...here is my guess. A circle is based on 360 degrees and these temples are all parts of a complete circle. There would be three 120 templates to equal 360. There would be four 90 templates to equal 360. There would be six 60 templates. There would be eight 45 templates to equal 360. There would be24 15 templates to equal 360. These parts could be traced..add on the seam allowance...then sewed together to make beautiful circles.This is one way I would use them!