Q33 of 68 Page 9

A flagstaff stands on a tower. At a point distant 60 m from the base of the tower, the top of the flagstaff makes an angle of 60° and the tower makes an angle of 30° at that very point. Find the height of the flagstaff

33


From the ∆DBC,





Now from the ∆ABC,





So, the height of the flagstaff


= AB – DB


=103.92 – 34.64


=69.28 m


Therefore, the height of the flagstaff is 69.28 m.


More from this chapter

All 68 →
31

An observer standing at a distance of 72 m from a building measures the angles of elevation of the top and foot of a flagstaff on the building as 54° and 50°. Find the height of the flagstaff. [tan54° = 1.376, tan50° = 1.192]

 32

A 20 m long flagstaff stands on a tower. At a point on the level ground the angles of elevations of the foot and top of the flagstaff are 30° and 60° respectively. Find the height of the tower.

 34

A statue 1.46 m tall, stands on the top of a pedestal. From a point on the ground, the angle of elevation of the top of the statue is 60° and from the same point, the angle of elevation of the top of the pedestal is 45°. Find the height of the pedestal (use = 1.73)

 35

The angle of elevation of the top of a hill at the foot of a tower is 60° and the angle of elevation of the top of the tower at the foot of the hill is 30°. If the tower is 50 m tall, what is the height of the hill?