- draw the points - you will see thet AC has the same M as BD - also AC = BD distance because it is a square - calculate the M of AC [tex] \frac{1 - ( - 3)}{ - 4 - ( - 1)} = \frac{4}{ - 3} = - \frac{4}{3} = m[/tex] - calculate AC distance [tex] \sqrt{ {(1 - ( - 3))}^{2} + {( - 4 - ( - 1))}^{2} } = \\ \sqrt{ {4}^{2} + {( - 3)}^{2} } = \\ \sqrt{25} = 5 = ac[/tex] - lets say d is (x,y) - now just make to equations with BD distance and M
