The angle of elevation of an aeroplane from a point on the ground is 60°. After flying for 15 second, the angle of elevation changes to 30°. If the Aeroplane is flying at a height of 4500 meter, then what is the speed (in m/s) of aeroplane?

The angle of elevation of the top of a tree 220 metres high from two points lies on the same plane are 30° and 45°. What is the distance (in metres) between the two points?

The distance between the tops of two building 38 metres and 58 metres and high is 52 metres. What will be the distance (in metres) between two building?

A ladder rests against a wall at a height of 10 meters. If the ladder makes 30° along the ground. Find the distance from the wall of the foot of the ladder.

Ramesh stands 40 meters away from the foot of a tower, if the angle of elevation of the sun is 60 degrees at that point, what will be the height of the tower?

The distance between two parallel poles is 40√3 m. The angle of depression of the top of the second pole, when seen from the top of first pole, is 30 °. What will be the height of second tower if the first pole is 100m long? 

The shadow of the tower becomes 60 meters longer when the altitude of the sun changes from 45 ° to 30 °. Then the height of the tower 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?