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.

From the top of an upright pole 17.75 m high, the angle of elevation of the top of an upright tower was 60⁰. If the tower was 57.75 m tall, how far away (in m) from the foot of the pole was the foot of the tower?

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? 

A man standing on the bank of river observes that the angle subtended by a tree on the opposite bank is 60°. When he retrieves 36 m from the bank, he find that the angle is 30°. The breadth of the river is

An Aeroplan flying horizontally at a height of 3 km. Above the ground is observed at a certain point on earth to subtend an angle of 60 °. After 15 sec flight, its angle of elevation is changed to 30 °. The speed of the Aeroplan (taking √3 = 1.732) 

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

A straight tree breaks due to storm and the broken part bends so that the top of the tree touches the ground making an angle of 30 ° with the ground. The distance from the foot of the tree to the point, where the top touches the ground is 10m. Find the total height of the tree 

The length of the shadow of a vertical tower on level ground increases by 10 meters when the altitude of the sun changes from 45° to 30°. Then the height of the tower is