The angles of depression of two consecutive kilometer posts on a straight road as seen from an aeroplane above it are `alpha and beta(alpha>beta)`.Find the height of the aeroplane above the road.

There are two cosecutive kilometre posts on a straight road.From an aeroplane flying vertically above the road in between the two km.Posts the angles of depression of the two km.Posts are seen to be 45^@ and 60^@ At what height is the aeroplane flying at the moment of observation?

From a window h m high above the ground in a street, the angles of elevation and depression of the top and foot of the other house on the opposite side of the street as alpha and beta respectively show that height of the opposite house is h(1+tan alpha cos beta)m .

A man sitting at a height of 20m in a tall tree on a small island in the middle of the river observes two poles directly opposite each other on the two banks of river and in line with the foot of the tree. If the angles of depression of the feet of the poles from a point at which the man is sitting on the three on either side of the river are 60° and 30° respectively. Find the width of the river.

If the angle of elevation of a cloud from a point h metre above the lake is alpha and the angle of depression of its reflection in the lake is beta , prove that the height of the cloud above the lake is (h(tan beta+tan alpha))/(tan beta- tan alpha)

The angle of elevation of the top of a tower as observed from a point on the ground is alpha and on moving 'a' metres towards the tower the angle of elevation is beta .Prove that the height of the tower is (atanalphatanbeta) / (tanbeta-tanalpha)

The angle of elevation of a post of height 55m as seen from the foot of a man standing on a road is 60^@ .Find the distance of the man from the post.

Two poles of equal heights are standing opposite each other on either side of the road,which is 80m 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.

From the top of a building 60m high the angle of depression of the top and the bottom of vertical lamp post an observed 30° and 60 ° respectively.Find The height of the lamp post.

There are two poles on each on either bank of a river just opposite to each other.One pole is 60m high.From the top of this pole the angles of depression of the top and the foot of the other pole are 30° and 60° respectively. Find the width of the river and the height of the other pole.

Two poles of equal heights are standing opposite to each other on either side of the road which is 80m 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 .