R = 3.5 (slider from -5 to 5, step 0.1)
C = (1.28, 2.38)
c = Circle(C, R)
F = Point(c)
b = Line(C, yAxis)
a = Segment(C, F)
d = Line(F, yAxis)
A = Point(d)
u = Vector(F, A)
e = Line(C, F)
f = Line(A, xAxis)
g = Line(F, xAxis)
D = Intersect(f, e)
h = Line(D, yAxis)
E = Intersect(g, h)
v = Vector(F, E)
D' = Mirror(D, F)
w = Vector(F, D')
corpo = Point(d)
i = Segment(F, corpo)