Question

The angle of elevation of the top of a tower from a point on the ground, which is 30 m away from the foot of the tower is 30°. The length of the tower is ____________.

Options

• `sqrt3` m

• `2sqrt3` m

• `5sqrt3` m

• `10sqrt3` m

Answer 1

The angle of elevation of the top of a tower from a point on the ground, which is 30 m away from the foot of the tower is 30°. The length of the tower is `underline(10sqrt3  "m")`.

Explanation:

Let the height of the tower, BC = h m

`therefore "in rt"  angle "ABC, tan"  30^circ = "BC"/"AB" => 1/sqrt3 = "h"/30`

`=> "h" = 30/sqrt3`

`=> "h" = 30/sqrt3 xx sqrt3/sqrt3`

`= (30sqrt3)/3`

`= 10 sqrt3` cm