SHORT ANSWER TYPE QUESTIONS
Q1. A tower stands vertically on the ground. From a point on the ground which is 20 m away from the foot of the tower, the angle of elevation of the top of the tower is found to be 60°. Find the height of the tower.
Sol. In the figure, AB is the tower,
∴ AB = h metres
In rt Δ ABC, we have:
⇒ |∵ tan 60° = √3 and AB = 20 m
⇒ h = 20√3 metre
Thus, the height of the tower = 20√3 m.
Q2. The angle of depression of the top and the bottom of a 9 m high building from the top of a tower are 30° and 60° respectively. Find the height of the tower and the distance between the building and the tower.
Sol. Let AB represents the building and CD be the tower.
∴ AB = 9 m
In right Δ BDC, we have:
In right Δ AEC, we have:
Thus, height of the tower = 13.5 m
Distance between the building and the tower = 7.8 m