From a point 12 meter above the water level, the angle of elevation of the top of a hill is 60° and the angle of depression of the base of the hill 30°. What is the height ( in meter) of the hill?

An electrician has to repair an electric fault on a pole of height 4 m. He needs to reach a point 1.3 m below the top of the pole to un dertake the repair work the length of ladder that he should use, which when inclined at an angle of 60° to the horizontal would enable him to reach the required positions is :

An observer who is 1.62-meter-tall is 45 meters away form a pole. The angle of elevation of the top of the pole from his eyes is 30°. The height ( in meter) of the pole is closet to:

An aero plane flying horizontally at a height of 3 km. Above the ground is observed at a certain point on earth to subtend an angle of 60⁰. After 15 sec flight, its angle of elevation is changed to 30⁰. The speed of the aero plane (taking √3=1.732)

If the angel of elevation of the sun decreases from 45⁰ to 30⁰, then the length of the shadow of a pillar increase by 60 m. The height of the pillar is