Using a pencil and ruler, draw a diagonal line from corner to corner
on the wrong side of all red and cream 2-7/8" squares.
With right sides together, layer a cream 2-7/8" square on a
red 2-7/8" square. Stitch a 1/4" seam on each side of the diagonal line
that you drew in Step 1. Cut apart on the drawn line and press seam
allowance toward the darker fabric. Trim points. Repeat seven times
more for a total of sixteen cream/red half-square triangles.
Arrange cream/red half-square triangles, green 2-1/2" squares, and cream 2-1/2" squares as shown
in Diagram 1. With right sides together and using a scant 1/4" seam, sew together to form rows as shown in Diagram 2. Sew rows as shown in Diagram 3 to finish the block.