Du cercle au deltoïde, en passant par le trifolium régulier
Author: Alain Rousseau

Construction de la tangente en un point du trifolium régulier à partir de ce point.
Cette construction très simple donne également la position du centre de courbure.

L = (194.9654072823006, -55.57842164014853)
M_1 = (176.12347086531497, -42.71415084826575)
p = Circle(L, M_1)
N = Point(p)
l = Line(N, L)
O = Point(p)
m = Line(L, O)
N' = Mirror(N, m)
O' = Mirror(O, l)
P = Midpoint(N', O')
lieu3 = Locus(P, O)
Q = Midpoint(N, L)
R = Midpoint(Q, N)
q = Circle(L, R)
n = Segment(L, O')
M = Point(lieu3)
a = Line(M, L)
b = OrthogonalLine(M, a)
B = Intersect(p, b, 1.0)
c = Segment(L, B)
C = Intersect(q, c, 1.0)
D = Intersect(p, b, 2.0)
f = Segment(D, L)
E = Intersect(q, f, 1.0)
d = Segment(E, M)
e = Segment(M, C)
F = Intersect(p, l, 2.0)
G = Midpoint(L, F)
g = OrthogonalLine(G, l)
H, I = Intersect(p, g)
h = Ray(L, I)
i = Ray(L, H)
j = Ray(L, N)
J = Intersect(d, j)
r = Segment(E, J)
s = OrthogonalLine(M, r)
K = Intersect(e, j)
t = Segment(K, C)
a_1 = OrthogonalLine(M, t)
S = Intersect(d, i)
b_1 = Segment(S, E)
c_1 = OrthogonalLine(M, b_1)
T = Intersect(e, i)
d_1 = Segment(C, T)
e_1 = OrthogonalLine(M, d_1)
U = Intersect(e, h)
f_1 = Segment(C, U)
g_1 = OrthogonalLine(M, f_1)
V = Intersect(d, h)
h_1 = Segment(E, V)
i_1 = OrthogonalLine(M, h_1)
k = Segment(B, D)
j_1 = Segment(M, L)