Two intersecting circles.............................u can make an equilateral triangle..............what Euclid did....................u can also make an ellipse from doing that........the blue diamond...................if u cut it horizontally........................along the X axis...............u can have two equilateral triangles........I can't save it with MS Word.......so I am using MS Paint.........not so good...........so the proportions are off...........it is the idea I am trying to convey.......................