I made this same pattern, but it was called a Strata Star. Since I'm mathematically challenged, my husband helped me mark the triangles on my 12" square. And I STILL made a mistake. When you are measuring, be sure to measure from the BOTTOM of the strip - there will be uncut fabric at the top of your triangle. I had to buy more fabric to finish my smaller triangles and cut my large ones down to the correct size, then all went together. But if hubby was not a machinist and total math whiz, I don't think I ever would have been able to finish - the directions for cutting were not at all clear. He measured down the side of my square, laid down masking tape to create the triangle, then very carefully cut across my ruler with the rotary to make sure the tape line was straight. And added an arrow so that I knew which side of the tape was the correct one to use. Good luck! Once you get the triangles cut, you're pretty much home free if all your seams match up!