\text{ Zostrojte rez kocky rovimou  }PQR. 

 \text{Postup

A = (-3, -3, 0)
B = (3, -3, 0)
C = Point(Circle[B, Distance[A, B], Segment[A, B]])
K, D, E, F, G, H, stenaABCD, stenaADHE, stenaABFE, stenaBCGF, stenaCDHG, stenaEFGH, hranaAD, hranaAB, hranaBC, hranaCD, hranaAE, hranaDH, hranaEH, hranaEF, hranaBF, hranaFG, hranaCG, hranaGH = Cube(A, B, C)
f = Ray(A, B)
P = Point(f)
g = Ray(G, H)
i = Ray(E, A)
R = Point(i)
Q = Point(g)