Question 148385
You can use the sine function for this problem.
The sine of the angle of elevation (63 degs) is found by dividing the side opposite the angle (that's the height (h) of the kite) by the hypotenuse (that's the length (20m) of the kite string.
{{{Sin(63) = h/20}}} Solve for h.
{{{h = 20*sin(63)}}}
{{{h = 17.8}}}meters
{{{h = 18}}}meters, rounded to nearest meter.
The unrealistic assumption here is that the kite string makes a straight line from the ground to the kite, but in reality, the string would assume the shape of a catenary (kind of like a parabola) curve.