When I input segment CD onto a graph, I get -0.4 as the slope or 15/-6. If the lines were parallel, they would need to have the same slope which they do not have. If they were perpendicular, they would need to have different slopes so, -2/5 and 5/2 which they do not. That leaves us with the only option of neither.
For the first movie he has 6 choices, then for the second since he has chosen the first there are only 5 left, then for the third there are only 4 choices left and so on.
Therefore the answer is 6!=6*5*4*3*2=720 orderings
