Question

the angle of elevation of the top of a tower from a certain point is 30 . if the observer moves 20m towords the tower, the angle of elevation of the top incresed by 15.find the height of the tower.

Answer 1

The height of the tower. is  27 m

Now, we write h/x = tan 45
i.e h/x = 1 
i.e h = x        ...........................1.

Now, h/(x+20) = tan 30
i.e  (x+20)/h = 1/tan 30

or (x+20) = 1.73h
or from equation 1 , 
h+ 20 = 1.73 h
20 = 1.73h - h
h = 20/0.73
or h = 27.39 = 27 m