The angle of elevation of the top of a hill at the foot of a tower is 60° and the angle of elevation
The angle of elevation of the top of a hill at the foot of a tower is 60° and the angle of elevation of the top of the tower from the foot of the hill is 30°. If the tower is 50 m high, what is the height of the hill?
Let be the height of hill. And be the tower of heightm. Angle of elevation of the top of hill from the foot of tower is 60° and angle of elevation of top of tower from foot of hill is 30°. Let and,
Here we have to find height of hill.
The corresponding figure is as follows
So we use trigonometric ratios.
In,
$\Rightarrow \quad \tan 30^{\circ}=\frac{C D}{A C}$
$\Rightarrow \quad \frac{1}{\sqrt{3}}=\frac{50}{x}$
$\Rightarrow \quad x=50 \sqrt{3}$
Again in $\triangle A B C$
$\Rightarrow \quad \tan 60^{\circ}=\frac{A B}{A C}$
$\Rightarrow \quad \sqrt{3}=\frac{h}{x}$
$\Rightarrow \quad h=x \sqrt{3}$
$\Rightarrow \quad h=150$
Hence the height of hill is $150 \mathrm{~m}$.