A drone hovers vertically above a fountain in a park. A controller is standing \(20 \ m\) away from the fountain. The distance from the controller to the drone is \(10 \ m\) longer than the drone's vertical height. Determine the vertical height of the drone.
Answer:
The vertical height of the drone is \(m\).
(Note: Round off the answer to \(1\) decimal place, if necessary.)