Two poles of equal height are standing opposite to each other on either side of a road, which is 28 metre wide. From a point between them on the road, the angle of elevation  of the top are 30° and 60°. The height of each pole is:-

The distance between two pillars is 120 meters. The height of one pillar is thrice of the other pillar. The angles of elevation of their tops from the midpoint of the line connecting their feet are complementary to each other. The height (in metres) of the pillar is (use : √3 = 1.732 )

A person from the top of a hill observes a vehicle moving towards him at a uniform speed. It takes 10 minutes for the angle of depression to change from 45 ° to 60 °. After this the time required by the vehicle to reach the bottom of the hill is 

A ladder is placed along a wall such that its upper end is touching the top of the wall. The foot of the ladder is 10 ft away from the wall and the ladder is making an angle of 60 ° with the ground. When a man starts climbing on it, it slips and now ladder makes an angle of 30° with ground. How much did the ladder slip? 

The angle of elevation of the sun, when the length of the shadow  of a tree √3 times the height of the tree, is:

An Aeroplan is flying horizontally at a height of 1.8 km above the ground. The angle of elevation of plane from point X is 60° and after 20 seconds, its angle of elevation from X becomes 30°, If point X is on ground, then what is the speed (in km / hr.) of Aeroplan? 

A kite is flying at a height of 50m. If the length of string is 100m then the inclination of string to the horizontal ground in degree measures is:

The shadow of a tower standing on a level plane is found to be 30 metre longer when the Sun's altitude changes from 60 ° to 45 °. The height of the tower is