Churn Dash? or center of a Balkan Puzzle block or Whirlpool block? I agree with Jan, you are missing the 8 lines to divide this up into 16 squares. I prefer handling HST's and squares vs. triangles. You could also do the rectangle with the square sewn on at the angle, press, and trim off at 1/4".
Here is a downloadable tutorial on the Whirlpool block that shows each step:
http://www.quiltmag.com/resources/qu...011-whirlpool/