Question

The angle of elevation of the top of a tower standing on a horizontal plane from a point A is α. After walking a distance d towards the foot of the tower the angle of elevation is found to be β. The height of the tower is

(a) $\frac{d}{cot\alpha +cot\beta }$

(b) $\frac{d}{cot\alpha -cot\beta }$

(c) $\frac{d}{\tan \beta -\tan \alpha }$

(d) $\frac{d}{\tan \beta +\tan \alpha }$

Answer 1

The given information can be represented with the help of a diagram as below.

Here, CD = h is the height of the tower. Length of BC is taken as x.

In ΔACD,

In ΔBCD.

From (1) and (2),

Hence the correct option is _.