A flagstaff 5 m high stands vertically on the top of a school building in Lucknow. From a point on the level ground, the angle of elevation of the top of the flagstaff is 60° and the angle of elevation of the top of the building is 45°. Find the exact height of the building (in m).

Question

Accepted Answer

5(√3 + 1)2. Let the building be h m tall and the ground distance be d m. tan 45 = h/d => d = h. tan 60 = h + 5/d = h + 5/h = √3 => h + 5 = h √3 => 5 = h(√3 - 1) => h = 5√3 - 1 = 5(√3 + 1)2 m (about 6.83 m).

A flagstaff 5 m high stands vertically on the top of a school building in Lucknow.
From a point on the level ground, the angle of elevation of the top of the flagstaff is 60° and the angle of elevation of the top of the building is 45°.
Find the exact height of the building (in m).

Step-by-Step Solution

Master this chapter in 30 minutes a day.

More Class 10 Heights and Distances practice

A flagstaff 5 m high stands vertically on the top of a school building in Lucknow.From a point on the level ground, the angle of elevation of the top of the flagstaff is 60° and the angle of elevation of the top of the building is 45°.Find the exact height of the building (in m).

Step-by-Step Solution

Master this chapter in 30 minutes a day.

More Class 10 Heights and Distances practice

A flagstaff 5 m high stands vertically on the top of a school building in Lucknow.
From a point on the level ground, the angle of elevation of the top of the flagstaff is 60° and the angle of elevation of the top of the building is 45°.
Find the exact height of the building (in m).