Best thing to do here is draw a picture. Draw the girl and the ballon for before and after. Mark in any lengths and angles that are mentioned then try to think of what mathematical rules might help you with the information given.
Can you help in providing steps in solving this? This is for class X - CBSE
A 1.2 m tall girl spots a balloon moving with the wind in a horizontal line at a height of 88.2 m from the ground. The angle of elevation of the balloon from the eyes of the girl at any instant is 60 degrees. After some time, the angle of elevation reduces to 30 degrees. Find the distance travelled by the balloon during the interval.