The angle of elevation of the top of a tower from a point A on the ground is 30^o. On moving a distance of 20 m towards the foot of the tower to a point B, the angle of elevation increase to 60^o.The height of the tower is-

The top of two poles of height 24m and 36 m are connected by a wire. If the wire makes an angle of 60° with the horizontal, then the length of the wire is 

From a point 20 m away from the foot of a tower, the angle of elevation of the top of the tower is 30°. The height of the tower is

The angle of elevation of an aeroplane from a point on the ground is 60°. After flying for 15 second, the angle of elevation changes to 30°. If the Aeroplane is flying at a height of 4500 meter, then what is the speed (in m/s) of aeroplane?

From the top of a lamp post of height x metres, two objects on the ground on the same side of it (and in line with the foot of the lamp post) are observed at angles of depression of 30° and 60°, respectively. The distance between the object is . The value of  x is:

From a point 12 meter above the water level, the angle of elevation of the top of a hill is 60° and the angle of depression of the base of the hill 30°. What is the height ( in meter) of the hill?

An observer who is 1.62-meter-tall is 45 meters away form a pole. The angle of elevation of the top of the pole from his eyes is 30°. The height ( in meter) of the pole is closet to:

Two ship are on the opposite of a light house such that all three of them are collinear. The angels of depression of the two ships from the top of the light house are 30⁰ and 60⁰. If the ships are m apart, then find the height of the light house (in m).