t = 0 (slider from 0 to 10, step 0.01)
vTrasl = 0.8 (slider from 0 to 2, step 0.1)
a = 0 (slider from 0 to 1, step 0.0010)
β: 3.141592653589793 / 2.0 * a
Spalla: (vTrasl * t, 4.0)
MI: Spalla + (-(1.414), -(1.414))
Mano = Rotate(MI, β, Spalla)
α = Angle(MI, Spalla, Mano)
b = Segment(Spalla, Mano)