Corde

Diamètre

Rayon

Cercle

Centre

Vocabulaire 

La corde [DE] est particulière,elle passe par le centre 
du cercle : [DE] est un diamètre de ce cercle.

Les points D et E sont diamétralement opposés.

La longueur d'un diamètre est égale à 2 fois celle du rayon.

O = Intersect(xAxis, yAxis)
D_1 = Point(yAxis)
c = Circle(O, D_1)
C = Point(c)
B = Point(c)
A = Point(c)
D = Point(c)
E = Mirror(D, O)
a = Segment(D, E)
b = Segment(O, A)
d = Segment(C, B)
F = (-3.9, 2.68)
G = (-3.18, 2.68)
g = Segment(F, G)
H = (4.04, -0.18)
I = (4.86, -0.18)
h = Segment(H, I)
J = (-3.82, 0.88)
K = (-3.12, 0.88)
i = Segment(J, K)
L = (3.98, 1.84)
M = (4.86, 1.86)
j = Segment(L, M)
N = (-3.86, -2.1)
P = (-2.64, -2.08)
k = Segment(N, P)
Q = (-3.14, 2.68)
R = Point(d)
u = Vector(Q, R)
S = (-2.62, -2.08)
T = Point(a)
v = Vector(S, T)
U = (4, 1.84)
V = Point(c)
w = Vector(U, V)
W = (4.0200000000000005, -0.2)
Z = Point(b)
z = Vector(W, Z)
A_1 = (-3.1, 0.88)
B_1 = (0, 0)
l = Vector(A_1, B_1)
f = false
m = false
n = Segment(D, O)
p = Segment(O, E)
o = false
q = true
e = false
C_1 = Point(n)
E_1 = Point(p)
r = Vector(W, E_1)
s = Vector(W, C_1)
F_1 = (-3.64, -3.6)