In triangle, D, F, E△DFE shown below, point GG is on start overline, E, F, end overline EF , and point HH is on start overline, D, F, end overline DF , and start overline, H, G, end overline HG is drawn perpendicular to hypotenuse start overline, D, F, end overline DF . If F, G, equals, 20FG=20, D, E, equals, 39DE=39, and G, H, equals, 15GH=15, find the length of start overline, F, D, end overline FD . Figures are not necessarily drawn to scale.