Sewjoyce,
You are getting the pattern directions from the Quilter's Cache site, right?
Marcia gives directions for cutting a 3 7/8" X 7 3/4" rectangle of each color. Instead of cutting the rectangle in half and then into hst, I put the two rectangles together. Then on the back of the lighter piece I marked lines to divide the piece:
I put a horizontal line at 3 7/8" and then on the diagonal from a corner to the horizontal line for each square. I then sewed 1/4" on each side of the horizontal lines. I cut the rectangle on the horizontal line and on each of the diagonal lines. Presto! 4 triangle corners. My triangle corners came out exactly 3 1/2" - to my surprise. :D
Marcia uses this method often when giving directions for her blocks. The trick here is getting the right measurements.
Connie