podobni(X1, Y1, X2, Y2, X3, Y3, X4, Y4, X5, Y5, X6, Y6, TRUE) :-
	rasstoyanie(X1, Y1, X2, Y2, R1),
	rasstoyanie(X2, Y2, X3, Y3, R2),
	rasstoyanie(X3, Y3, X1, Y1, R3),
	rasstoyanie(X4, Y4, X5, Y5, R4),
	rasstoyanie(X5, Y5, X6, Y6, R5),
	rasstoyanie(X6, Y6, X4, Y4, R6),
	TRUE = (R1*R5 == R2*R4), (R1*R6 == R4*R3).

rasstoyanie(X1, Y1, X2, Y2, R) :-
	R is ((X2-X1)*(X2-X1) + (Y2-Y1)*(Y2-Y1)).