A = (0, -1)
B = (1, -1)
poly1, a, b, c, d, C, D = Polygon(A, B, 4.0)
E = (1, -1)
F = (2, -1)
poly2, e, f, g, h, G, H = Polygon(E, F, 4.0)
poly3, d_1, g_1, i, j, I, J = Polygon(D, G, 4.0)