Q = (2, -1)
P = (-1, 5)
g = Line(P, Q)
m = Slope(g)
C = (-3, 2)
S: 1 / (1 + m^(2)) * {{1 - m^(2), 2 * m}, {2 * m, m^(2) - 1}}
v: P - S * P
A = (-4, -1)
B = (-1, 2)
B': S * B + v
Vieleck1, q, r, p = Polygon(C, A, B)
A': S * A + v
C': S * C + v
Vieleck2, q', p', r' = Polygon(A', C', B')