For block 7 you will use:
8) 4" background squares
4) 4" red squares
4) 4" blue squares
Draw a diagonal line on the back of the background squares.
Match the four red squares with four background squares.
Match the four blue squares with the remaining four background squares.
Place the squares right sides together with the outside edges aligned.
Sew 1/4 inch on each side of the line.
Cut on the line.
Square to 3 1/2" and trim the corners from each end of the seam to eliminate bulk.
Press toward the darker fabrics.
Use the photo above to arrange and sew the half square triangles to create the block.