
Let K be the kite and the string is tied to point P on the ground.
In ∆KLP,
\(\frac{KL}{KP} = sin60°\)
\(\frac{60}{ KP} = \frac{\sqrt3}2\)
\(KP = \frac{120}{\sqrt3} = 40\sqrt3 \,m\)
Hence, the length of the string is \(40\sqrt3 \,m\).
The shadow of a tower on level ground is $30\ \text{m}$ longer when the sun's altitude is $30^\circ$ than when it is $60^\circ$. Find the height of the tower. (Use $\sqrt{3}=1.732$.)