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

A = (-2.1, -0.22)
B = (3.2, 0.68)
a = Segment(A, B)
b = OrthogonalLine(A, a)
c = OrthogonalLine(B, a)
D = Point(b)
d = OrthogonalLine(D, b)
C = Intersect(c, d)
e = Segment(A, D)
f = Segment(D, C)
g = Segment(C, B)
α = Angle(D, A, B)
β = Angle(A, B, C)
γ = Angle(B, C, D)
δ = Angle(C, D, A)