I combined traditional piecing and needle-turn appliqué for this one. I cut out 8 each of the quarter circles and sewed their straight sides into the seams while piecing the quadrants and borders together. It is important to remember to turn the edges under while the straight sides and the round sides meet while doing this. Then I used needle-turn appliqué to finish the round sides.
This is block # 157 and it has 16 pieces.