Video3: TRICK- parallel v/s perpendicular

And this example, you see a slope of 5 over 7, and a slope of 7 over 5 are these lines parallel to perpendicular. In order to be perpendicular to conditions must be met, the numbers have to be flipped. The 7 has to be on the top the 5 has to be on the bottom, which it is. But the sines have to be different. It has to be a positive sign here and a negative sign here, which it is not. So that is a trick, so that means it is neither.