I agree with justabitcrazy. I made a jeans quilt like that. We machine zigzagged around the circle (the one above looks like it was cut from a pieced 4 patch)part of the square. What you did was to draw the largest square on the inside of each circle (wrong side of material) Then you stitched the circles together by stitching along the line. Then placed a piece of material on the inside of the square and stitched the curved part of the circle down around that material. I know what I am trying to say but not sure I am saying it right.