Let K be the kite and the string is tied to point P on the ground.
\\(\\begin{array}{l}{\ ext { In } \\Delta \\mathrm{KLP}_{,}} \\\\ {\\frac{\\mathrm{KL}}{\\mathrm{KP}}=\\sin 60^{\\circ}} \\\\ {\\frac{60}{\\mathrm{KP}}=\\frac{\\sqrt{3}}{2}} \\\\ {\\mathrm{KP}=\\frac{120}{\\sqrt{3}}=40 \\sqrt{3} \\mathrm{m}} \\\\ {\ ext { Hence, the length of the string is } 40 \\sqrt{3} \\mathrm{m} \ ext { . }}\\end{array}\\)