Question

The angle of elevation of the top of a tower from a point on the ground 60 m away from the foot of tower is 30°. The height of tower is ______.

Options

• `10sqrt(3)` m

• `20sqrt(3)` m

• `40sqrt(3)` m

• `60sqrt(3)` m

Answer 1

The angle of elevation of the top of a tower from a point on the ground 60 m away from the foot of tower is 30°. The height of tower is `underlinebb(20sqrt(3)  m)`.

Explanation:

Let h = height.

`tan 30^circ = h/60`.

Since `tan 30^circ = 1/sqrt(3)`,

`h = 60 xx 1/sqrt(3)` 

= `60/sqrt(3)`

= `(60sqrt(3))/3`

= `20sqrt(3)` m