Final answer:
The rate at which the string lengthens is directly proportional to the rate at which the angle increases.
Step-by-step explanation:
The rate at which the string lengthens and the rate at which the angle increases are related in this scenario. Since the kite is flying at a constant height above the ground, the increase in angle corresponds to the increase in horizontal distance between the person flying the kite and the kite itself. As the kite moves further away, the string lengthens and the angle increases. Therefore, the rate at which the string lengthens is directly proportional to the rate at which the angle increases.
This means that as the angle increases at a faster rate, the string lengthens at a faster rate as well. Similarly, if the angle increases at a slower rate, the string lengthens at a slower rate too.