KJ is the hypotenuse of the right triangle KJN, therefore:KJ^2 = KN^2 + JN^233^2 = (6sqrt10)^2 + JN^21089 = 360 + JN^2JN^2 = 729JN = 27 The figure is a trapezoid, since GH // JI, and MN is perpendicular to HI. Therefore GN = JN = 27. The length of GJ = 54.