A = (-2, 0)
B = (-1, 2)
u = Vector(A, B)
C = (2, 4)
v = Vector(B, C)
A' = (7, 4)
w = Vector(C, A')
B': A' - u
C': B' - v
a = Vector(A', B')
b = Vector(B', C')
c = Vector(C', A)