A kite is flying above a point on the ground. The string from the kite to a person's hand is \(10 \ m\) longer than the kite's vertical height above the person's hand. The kite is horizontally \(20 \ m\) away from the point directly above the person's hand. Determine the vertical height of the kite.
Answer:
The vertical height of the kite is \(m\).
(Note: Round off the answer to \(1\) decimal place, if necessary.)