Assemble Pillow (front and back)
1. Sew together one red triangle and one blue triangle along one short edge to make a large red triangle unit (Diagram 1). Press seam toward red triangle.
2. Join one green triangle and one blue triangle along one short edge to make a large green triangle unit (Diagram 2). Press seam toward green triangle.
3. Sew together red and green triangle units to make pillow top. The pillow front should be 18-1/2" square including seam allowances.4. Repeat steps 2 through 3 to make pillow back.