1. Referring to Diagram 1, sew together a white-and-blue print medium triangle and a blue print medium triangle along short edges to make a triangle pair. Press seam toward blue print medium triangle.
2. Add a matching white-and-blue large triangle to long edge of triangle pair to make a pieced square (Diagram 2). Press seam toward large triangle.
3. Repeat steps 1 and 2 to make four matching pieced squares.
4. Referring to Diagram 3, sew together the four pieced squares in pairs. Press seams in opposite directions. Join pairs to make a Pinwheel block. Press seam in one direction. The Pinwheel block should be 6-1/2" square including seam allowances.
5. Repeat steps 1-4 to make 13 Pinwheel blocks total.