I made these blocks a few weeks ago, for my green quilt. I wasn't too happy with them and I put them in a box. Some day I will try another version.
I made two sets of strips, cut wedges with the fan ruler and combined them.
The measurements include seam allowances.
The trick to get rounded blocks is to use the same fabric for the top and bottom strips of the set and for the background (the squares in the corners of every block).
The final block measures about 15.5'' x 15.5''.
Here is the tutorial on how to turn the dresden blocks into octagons then in squares.
The possibilities are endless. Happy Quilting!