Question 11824
the 2 diagonal lines will be joining A to C and the other is joining B to D.


For AC, find the gradient
For BD, find the gradient.


If any 2 lines are perpendicular, then their gradients multiplied together will equal -1.


so once you have found the gradients, mutliply these 2 numbers together. Do you get -1? YES/NO...answer.


jon.