(Ignore the little unpieced triangles. We'll rotary cut them.)
Following the numbers, foundation piece each numbered section and trim the seam allowances to 1/4".
Out of background fabric, cut 2 squares 2 3/8" x 2 3/8" and cut each in half on the diagonal.
Sew together the three center sections.
Attach the four side sections.
Finally sew on the four background fabric triangles.



