M : Ex 126. Le milieu du lac
Author: Frédéric Chanez

Centre = (1, -2)
Marin = (-3, 4)
c = Circle(Centre, Marin)
a = Segment(Centre, Marin)
Yverdon = Point(c)
b = Segment(Centre, Yverdon)
Corde = Segment(Marin, Yverdon)
M = Point(Corde)
e = OrthogonalLine(M, Corde)
A = Intersect(c, e, 2)
d = Segment(M, A)
g = Segment(M, Centre)
h = CircleArc(Centre, Yverdon, Marin)
étape = 1 (slider from 1 to 5, step 1)
α = Angle(g, Corde)