O: (0, 0, 0)
a = Sphere(O, 6.371)
M = PointIn(a)
B = PointIn(a)
A = PointIn(a)
b = Plane(M, A, B)
c = IntersectPath(b, a)
d: z = 0
e = IntersectPath(d, a)
f = Segment(B, A)
C_1 = Midpoint(f)
g = OrthogonalPlane(C_1, f)
h = IntersectPath(g, b)
D, E = Intersect(h, c)
C = Midpoint(E, D)
p = CircleArc(C, A, B)
α = Angle(B, C, A)
i = Segment(C, B)
j = Segment(C, A)
texte1: "L=" + p + ""
H, I = Intersect(xAxis, e)
J, K = Intersect(yAxis, e)