Déplacer les sommets  
 et observer les propriétés du losange
(celles qui ne changent pas)

E = (-2, 3)
F = (2.56, 2.94)
c = Circle(E, F)
H = Point(c)
d = Circle(F, 4)
e = Circle(H, 4)
a = Segment(E, F)
f = Segment(E, H)
g = Circle(F, E)
h = Circle(H, E)
G = Intersect(g, h, 2)
b = Segment(F, G)
i = Segment(H, G)