From a point on the ground, 30 m away from the foot of tower, the angle of elevation of the top of the tower is 30°. The height of the tower is
A. 30 m

B. 10√3 m

C. 10 m

D.30√3 m

Let AB be the tower and C be the point on the ground, 30m away from B. Given that, BC = 30m, the angle of elevation, ∠ACB = 30°. Join A, C and B,C. We get a right-angled triangle. We use trigonometric ratio tan taking AB as the height and BC as the base. In ∆ABC,

or,

So, the correct option is (B).