Question

A man sitting in an areoplane observes
that the angle of depression of two
temple 2 km a pour t are 6010. 500. If
the plane is exactly above the middle
point of the Ime joining the temple, then
find the height​

Answer 1

   

    

  

    

      

Let E and D be the two positions of the plane and A be the point of observation. 

Let ABC be the horizontal line through A.

It is given that angles of elevation of the plane in two positions E and D are a point A are 60o and 30o respectively.

∠EAB=60o, ∠DAB=30o. 

It is also given that EB=30003 m.

In ΔABE,tan60o=ABBE

13=AB30003

AB=3000 m

In ΔACD,tan30o=ACDC

31=AC30003

AC=9000 m

Distance =BC=AC–AB=9000–3000=6000 m

The plane travels 6 km in 30 second,

Then the speed of the plane =306000=200m/sec