Answer:
107.9 ft
Step-by-step explanation:
Imagine Kite is a point A. The person ,who keeps the string is point B.
The height of flying is AC=85 ft. So we have right triangle ABC :angle C=90 degrees, angle B is 52 degrees. Length of AB (triangle ABC hypotenuse) is the length of the string.
AB=AC/sinB=85/sin52=107.8665...=approx 107.9 ft