Question 1 of 5
A kite is flying at the end of a taut string that is 80 feet long. The string makes an angle of with the level ground. Approximately how high above the ground is the kite?
Explanation
The string, the ground, and the kite’s height form a right triangle. The 80-foot string is the hypotenuse, and the height of the kite is opposite the angle. Use sine:
so
Since , the height is about
Therefore, the kite is approximately feet above the ground.
Concept summary
In a right triangle, sine relates an angle to the ratio of the opposite side and the hypotenuse: . Use it when the angle and hypotenuse are known and the opposite side is needed.