Question

From the top of a tower of height 100 m, a bird sees an airplane at an angle of elevation of 30°. The bird sees the reflection of the plane on a river at an angle of depression of 60°. If the distance between the bird and the plane is 300 m, find the height at which the plane was flying above the ground level? ​

Answer 1

Step-by-step explanation:

its will br 300 defreeew will be there

Answer 2

Answer:

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

Then,

∠ACB=30o,∠AED=45o,AC=100 m,EF=20 m

In right △ACB, 

we have,

sin30o=ACAB

21=100AB

AB=50 m

AD=AB−BD

AD=50−EF

AD=50−20=30 m

In right △ADE, we have,

sin45o=AEAD

21=AE30

AE=302=42.3 m

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