Question

From the top of a cliff 20 m high the angle of elevation of a tower is found to be equal to the angle of depression of the foot of the tower. Find the height of the tower

Answer 1

$\frac{2\theta }{d}=tan\alpha$
$\frac{h}{d}=tan\alpha$
$\therefore \frac{2\theta }{d}=\frac{h}{d}$
$\Rightarrow h=20$
$\therefore$ Height of tower = h +20
= 20 + 20 = 40 m