Question

A kite is flying on 39 feet of string. How high is it above the ground if it’s height is 22 feet more than the horizons distance from the person flying it. Assume that the string is being held at ground level.

Answer 1

about 36.3 feet

Explanation:

Let x represent the height of the kite in feet. Then (x-22) is the horizontal distance to the kite. The Pythagorean theorem tells you the string length is related to these distances by ...

... 39² = x² + (x-22)²

... 2x² -44x -1037 = 0 . . . . rearrange to standard form

Using the quadratic formula, the positive solution is ...

... x = (-b+√(b²-4ac))/(2a) . . . . for a=2, b=-44, c=-1037

... x = (44 + √((-44)² -4(2)(-1037)))/(2·2)

... x = 11 + √639.5 ≈ 36.288

The kite is about 36.3 feet above the ground.