A = (1, 5)
B = (1, 3)
C = (2, 3)
poly1, c, a, b = Polygon(A, B, C)
D = (2, 1)
A' = Rotate(A, 270*°, D)
B' = Rotate(B, 270*°, D)
C' = Rotate(C, 270*°, D)
poly1', c', a', b' = Polygon(A', B', C')