Height and Distance - General Aptitude

Q1:

An observer 1.6 m tall is 203 away from a tower. The angle of elevation from his eye to the top of the tower is 30°. The height of the tower is:

A 21.6 m

B 23.2 m

C 24.72 m

D None of these

ANS:A - 21.6 m

Let AB be the observer and CD be the tower. Draw BE  CD. Then, CE = AB = 1.6 m,       BE = AC = 203 m.

DE = tan 30° = 1
BE 3
 DE = 203 m = 20 m.
3
 CD = CE + DE = (1.6 + 20) m = 21.6 m.