Question 4189
first, find the gradient of the line that passes through the 2 points --> look at my lessons on this topic on this site. They are easy to follow and explain it well.


Once you have that, you need to know that 2 lines that are perpendicular, will have gradients m1 and m2 such that m1*m2 = -1.


So, if your gradient is 3, then the perpendicular line has a gradient of -1/3.


Jon