yA = 2 (slider from -10 to 10, step 0.1)
A: (2, yA)
O = (0, 0)
c = Line(O, A)
raggio = 1 (slider from 0 to 5, step 0.1)
e = Circle(A, raggio)
B = Intersect(e, c, 2)
C = Intersect(e, c, 1)
luogo1 = Locus(B, yA)
luogo2 = Locus(C, yA)
a: y = y(C)
b: y = y(B)
D = Intersect(a, f)
E = Intersect(b, f)
poli1, a_1, c_1, d = Polygon(C, D, A)
poli2, e_1, a_2, b_1 = Polygon(A, B, E)
F = (2, 0)
θ = Angle(F, O, C)