Q = (7, 3)
R = (6, 6)
P = (3, 2)
P_1, b, c, a = Polygon(P, Q, R)
M: {{-0.6, 0.8}, {0.8, 0.6}}
P': M * P
Q': M * Q
R': M * R
Vieleck1, r', p', q' = Polygon(P', Q', R')