Question

A girl was standing on a road near a building. She was 1410 m away from the building and able
to see the top of the building from the road in such a way that top of the tree, which is in between
her and the building, was exactly in line of sight with the top of the building. The tree height is
10m and it is 30m away from the girl
. Find the height of the building.​

Answer 1

Step-by-step explanation:

Let A be the position of the bird and E and C be the positions of the girl and the boy, respectively.

Then,

∠ACB=30

o

,∠AED=45

o

,AC=100 m,EF=20 m

In right △ACB,

we have,

sin30

o

=

AC

AB

2

1

=

100

AB

AB=50 m

AD=AB−BD

AD=50−EF

AD=50−20=30 m

In right △ADE, we have,

sin45

o

=

AE

AD

2

1

=

AE

30

AE=30

2

=42.3 m

Therefore, the distance of bird from the girl is 42.3 m.

solution

Answer 2

above answer is not relevant to the question