Two circles

This is a strange relationship. When bending curves are aligned at their centre points, the curve endpoints lay on two circles! Circle diameter = 4/5 of curve length.
Download .ghx file:
UPDATED WITH CORRECT FILE
http://www.omkrets.se/grasshopper/MN-cornu-script.zip
Early test here:http://thegeometryofbending.blogspot.com/2008/11/arranging-curves.html