Originally Posted by ghostrider

Oh wait, do you mean sew the white squares in the corners of the rectangle with a diagonal line and then flip the down pointing point up to make a triangle? That would work, yes, but trim off the two layers (color and white) that are under the top white triangle (trim to a ¼" seam). Make sense? The only difference would be no vertical seams in the top and bottom pieces. Sounds pretty smart to me!