A Navy captain going away from a lighthouse at the speed of 4[(73) -1] m/s. He observes that it takes him 1 minute to change the angle of elevation of the top of the lighthouse from 60 ° to 45 °. What is the height (in meters) of the lighthouse? 

From an observation tower ‘h’ meter above the level of river, the angle of depression of a point on the near shore is A^° and that of a point directly on the far shore is B^°. Find the width of the river.

A helicopter, at an altitude of 1500 metre, finds that two ships are sailing towards it, in the same direction. The angles of depression of the ships as observed from the helicopter are 60° and 30° respectively. Distance between the two ships, in metre is

From a tower 125 metres high the angle of depression of two objects, which are horizontal line through the base of the tower are 45° and 30° and they are on the same side of the tower. The distance (in metres) between the objects 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 

A vertical stick 12 cm long casts a shadow 8 cm long on the ground. At the same time, a tower casts a shadow 40 m long on the ground. The height of the tower is 

The angle of elevation of the top of a building at a distance of 70 m from its foot on a horizontal plane is found to be 60°. Find the height of the building.

The angle of elevation of ladder leaning against a house is 60° and the foot of the ladder is 6.5 meters from the house. The length of the ladder is