As observed from the top of a light house, 100 m high above sea level, the angle of depression of a ship, sailing directly towards it, changes from `30^@` to `45^@`. Determine the distance travelled by the ship during the period of observation.

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.

From the top of a 7m 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.

From the top of a hill 200 m high, the angles of depression of the top and the bottom of a pillar are 30^@ and 60^@ respectively. Find the height of the pillar and its distance from the hill.

A man on the deck of a ship is 16 m above water level. He observes that the angle of elevation of the top of a cliff is 45^@ and the angle of depression of the base is 30^@ . Calculate the distance of the cliff from the ship and the height of the cliff.

A man on the deck of a ship is 12 m above water level. He observes that the angle of elevation of the top of a cliff is 45^@ , and the angle of depression of the base is 30^@ . Calculate the distance of the cliff from the ship and the height of the cliff.

A man is standing on the deck of a ship, which is 8 m above water level. He observes the angle of elevation of the top of a hill as 60^@ and the angle of depression of the base of the hill as 30^@ . Calculate the distance of the hill,from the ship and the height of the hill.

A man in a boat rowing away from a cliff 150m high takes 2 minutes to change the angle of elevation of the top of the cliff from 60^@ to 45^@ . The speed of the boat is

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.). Find the distance travelled by the balloon during the interval.

From a building 60 metres high the angle of depression of the top and bottom of lamppost are 30^@ and 60^@ respectively. Find the distance between lamp post and building. Also find the difference of height between building and lamp post.

From the top of a building 15 m high, the angle of elevation of the top of a tower is found to be 30^@ . From the bottom of the same building, the angle of elevation of the top of the tower is found to be 60°. Find the height of the tower and the distance between the tower and the building.