The perpendicular bisector would be the line that connects with the line HI at a 90 degree angle and in the mid-point. This means that we would have to find the slope of the line HI and take the opposite. The slope of HI is 1/3. This means that the slope of the perpendicular line is -3. Now we must solve for the line that crosses through the midpoint. y=mx+b we know that m=-3 and that the midpoint is at -1,3 so x=-1 and y=3. 3=(-3)-1+b. We then solve for b and find it to be 0. So the final answer is y= -3x
