Question

A plane is observed to be approaching the airport. It is at a distance of 12 km from the point of observation and makes an angle of elevation of 60°. The height above the ground of the plane is ____________.

Options

• `6 sqrt3` m

• `4 sqrt3` m

• `3 sqrt3` m

• `2 sqrt3` m

Answer 1

A plane is observed to be approaching the airport. It is at a distance of 12 km from the point of observation and makes an angle of elevation of 60°. The height above the ground of the plane is `underline(6 sqrt3  "m")`.

Explanation:

Here distance Ac = 12 km

In rt `angle "ABC, sin"  60^circ = "BC"/"AC"`

`=> sqrt3/2 = "BC"/12`

`=> 2  "BC" = 12 sqrt3`

`=> "BC" = 6 sqrt3` km