The profile of the cables on a suspension bridge may be modeled by a parabola. the central span of the bridge is 12401240 m long and 142142 m high. the parabola y equals 0.00037 x squared (y=0.00037x^2) gives a good fit to the shape of the cables, where |x| less than or equals 620, and x and y are measured in meters. approximate the length of the cables that stretch between the tops of the two towers.