A vertical tower stands on a bank of a river. From the opposite bank the angle of elevation of the top is 60°. From a point 20 m further back from that bank, the angle is 30°. Find the height of the tower (in m).

Question

Accepted Answer

10 √3. Let height h, river width x. tan 60 = h/x => x = h√3. tan 30 = h/x+20 => x+20 = h √3. So h √3 - h√3 = 20 => 2h√3 = 20 => h = 10 √3 m.

A vertical tower stands on a bank of a river.
From the opposite bank the angle of elevation of the top is 60°.
From a point 20 m further back from that bank, the angle is 30°.
Find the height of the tower (in m).

Step-by-Step Solution

Master this chapter in 30 minutes a day.

More Class 10 Heights and Distances practice

A vertical tower stands on a bank of a river.From the opposite bank the angle of elevation of the top is 60°.From a point 20 m further back from that bank, the angle is 30°.Find the height of the tower (in m).

Step-by-Step Solution

Master this chapter in 30 minutes a day.

More Class 10 Heights and Distances practice

A vertical tower stands on a bank of a river.
From the opposite bank the angle of elevation of the top is 60°.
From a point 20 m further back from that bank, the angle is 30°.
Find the height of the tower (in m).