AC

BC

AM

AN

MN

AM/AB

AN/AC

MN/BC

AB

Bouger le point M permet de glisser la droite parallèle (MN). 
En emenant M derrière A, on obtient la configuration papillon.
Les points A, B et C permettent de déformer le triangle.
On remarque que les quotients restent toujours égaux entre eux.

A = (1.775397154623734, -0.9107938968104177)
B = (9.78226542876312, -0.296139907637957)
C = (12.930455510945084, -5.422952333075231)
a = Line(A, C)
b = Line(A, B)
c = Line(B, C)
M = Point(b)
d = Line(M, c)
N = Intersect(a, d)
AB = Distance(A, B)
AC = Distance(A, C)
BC = Distance(B, C)
AM = Distance(A, M)
A4: AM
AN = Distance(A, N)
B4: AN
MN = Distance(M, N)
C4: MN
A2: 8
A6: A4 / A2
B2: 12
B6: B4 / B2
C2: 6
C6: C4 / C2
e = Segment(N, M)
f = Segment(C, B)
g = Segment(A, M)
h = Segment(A, B)
i = Segment(A, N)
j = Segment(A, C)
poly1, m, a_1, n = Polygon(A, N, M)
D = Intersect(g, i)
poly2, b_1, d_1, c_1 = Polygon(D, C, B)
k = Circle(A, 12)
p = Circle(B, 6)
q = Circle(A, 12)
r = Circle(B, 6)