過圓上一點的弦中點軌跡
Author: 詩琦

定點 = (2, 4)
圓心 = (1, 2)
O = Circle(圓心, 3)
C = Point(O)
a = Line(C, 定點)
D = Intersect(O, a, 2)
E = Midpoint(C, D)
F = Point(O)
b = Line(F, 定點)
G = Intersect(O, b, 2)
H = Midpoint(G, F)
I = Point(O)
d = Line(I, 定點)
J = Intersect(O, d, 2)
K = Midpoint(J, I)
L = Point(O)
e = Line(L, 定點)
M = Intersect(O, e, 2)
N = Midpoint(M, L)
loc1 = Locus(E, C)