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? 

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 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:

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 

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 angle of elevation of the top of a tower from two points A and B lying on the horizontal through the foot of the tower are 159 and 30° respectively. If A and B are on the same side of the tower and AB = 48 meter, then the height of the tower is; 

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 

If the angle of elevation of a balloon from two consecutive kilometer-stones along a road are 30° and 60° respectively, then the height of the balloon above the ground will be