Question

A flag-staff stands on the top of a 5 m high tower. From a point on the ground, the angle of elevation of the top of the flag-staff is 60° and from the same point, the angle of elevation of the top of the tower is 45°. Find the height of the flag-staff.

Answer 1

Let be the tower height of m. flag height is m and an angle of elevation of top of tower is 45° and an angle of elevation of the top of flag is 60°.

Let, m and m and,

We have the corresponding angle as follows

So we use trigonometric ratios.

In a triangle,

Again in a triangle,

Hence the height of flag is m.