Question

A boy standing on a horizontal plane finds a kite flying at a distance of 150 m from him at angle of elevation 30 degree from him at angle of elevations 30 degree a girl standing on the roof of 30 meter high building find the angle of elevation of the same kite to us both boy and girl are on opposite site of the kite find the distance of the kite from the girl

Answer 1

Given:

distance between boy and kite = 150m

the angle of elevation from boy = 30°

height of the roof = 30m

the angle of elevation from girl = 30°

To Find:

The distance of the kite from the girl

Solution:

we know,

In a right triangle

sin Ф = P / H

let KO = x

KG = The distance of the kite from the girl.

In Δ BAK,

sin 30° = x + 30 / 150

1/2 = x+30 / 150

x+30 = 75

x = 45m

Now,

In Δ GOK,

sin 30 = x / KG

1/2 = x / KG

KG = 2 * x

KG = 2 * 45 = 90m

So, The distance of the kite from the girl is 90m.