Question 78400
distance between (-9,3) and (-1,-5)= sqrt[(-1+9)^2 + (-5-3)^2]

                                  = sqrt[8^2 + (-8)^2]

                                  = sqrt(64+64)

                                  = sqrt(64*2)

                                  = sqrt(64)*Sqrt(2)

                                  = 8 sqrt(2) units