a = 2 (slider from 0 to 6, step 0.5)
C = (0.32, -0.1)
c = Circle(C, 1.0)
A = Point(c)
u = Vector(C, A)
B = Point(c)
v = Vector(C, B)
A' = Translate(C, Vector[a * u])
B' = Translate(C, Vector[(6.0 - a) * v])
C' = Translate(C, Vector[a * u + (6.0 - a) * v])
poly1, c_1, a', c', b' = Polygon(C, A', C', B')