1.   A circus artist is climbing a 20 m long rope, which is tightly stretched and tied from the top of a vertical pole to the ground. 
Find the height of the pole, if the angle made by the rope with the ground level is 30° (see Fig. 9.11).

2.   A  tree  breaks  due  to  storm  and  the  broken  part bends so that the top of the tree touches the ground making an angle 30° 
with it. The distance between the  foot  of  the  tree  to  the  point  where  the  top touches the ground is 8 m. Find the height of 
the tree.

3.   A contractor plans to install two slides for the children to play in a park. For the children below the age of 5 years, she prefers
 to have a slide whose top is at a height of 1.5 m, and is inclined at an angle of 30° to the ground, whereas for elder children, she wants
 to have a steep slide at a height of 3m, and inclined at an angle of 60° to the ground. What should be the length of the slide in each case?
 
4.   The angle of elevation of the top of a tower from a point on the ground, which is 30 m away from the foot of the tower, is 30°.
 Find the height of the tower.
 
5.   A kite is flying at a height of 60 m above the ground. The string attached to the kite is temporarily tied to a point on the ground.
 The inclination of the string with the ground is 60°. Find the length of the string, assuming that there is no slack in the string.
 
6.   A 1.5 m tall boy is standing at some distance from a 30 m tall building. The angle of elevation from his eyes to the top of the building
 increases from 30° to 60° as he walks towards the building. Find the distance he walked towards the building.
 
7.   From a point on the ground, the angles of elevation of the bottom and the top of a transmission tower fixed at the top of a 20 m high
 building are 45° and 60° respectively. Find the height of the tower.
 
8.   A statue, 1.6 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.

9.   The angle of elevation of the top of a building from the foot of the tower is 30° and the angle of elevation of the top of the tower
 from the foot of the building is 60°. If the tower is 50 m high, find the height of the building.
 
10.   Two poles of equal heights are standing opposite each other on either side of the road, which is 80 m wide. From a point between them
 on the road, the angles of elevation of the top of the poles are 60° and 30°, respectively. Find the height of the poles and the distances 
 of the point from the poles.
 
 11.   A TV tower stands vertically on a bank of a canal. From a point on the other bank directly opposite the tower, the angle  of 
 elevation  of  the  top  of  the tower is 60°. From another point 20 m away from this point on the line joing this point to the foot of
 the tower, the angle  of  elevation  of  the  top  of  the tower is 30° (see Fig. 9.12). Find the height of the tower and the width of the 
 canal.
 
 12.   From the top of a 7 m high building, the angle of elevation of the top of a cable tower is 60° and the angle of depression of its
      foot is 45°. Determine the height of the tower.
	  
13.   As observed from the top of a 75 m high lighthouse from the sea-level, the angles of depression of two ships are 30° and 45°.
	If one ship is exactly behind the other on the same side of the lighthouse, find the distance between the two ships.
	
14.   A 1.2 m tall girl spots a balloon moving with the wind in a horizontal line at a height of 88.2 m from the ground. The angle of 
	elevation of the balloon from the eyes of the girl at any instant is 60°. After  some  time,  the  angle  of elevation reduces to
	30° (see Fig. 9.13). Find  the  distance  travelled  by  the balloon during the interval.
	
15.   A straight highway leads to the foot of a tower. A man standing at the top of the tower observes a car at an angle of depression 
	of 30°, which is approaching the foot of the tower with a uniform speed. Six seconds later, the angle of depression of the car is 
	found to be 60°. Find the time taken by the car to reach the foot of the tower from this point.
	
16.   The angles of elevation of the top of a tower from two points at a distance of 4 m and 9 m from the base of the tower and in the 
	same straight line with it are complementary. Prove that the height of the tower is 6 m.