7 Jul
2017
7 Jul
'17
3:56 p.m.
Take a triangular number and multiply by 4. For example, 45x4=180. Create four copies of all squares up to that number. 4 copies of squares 1-180 gives 720 squares. It is possible to arrange the squares into a lune. http://community.wolfram.com/groups/-/m/t/1141202 has a picture. (△×4)^2 ×4 = lens. Might be called a vesica piscis. --Ed Pegg Jr