Question

A man standing on a bank of a river found that the angle of elevation of a tree on the other bank of the river is 60° . By retiring 40m back he found the angle of elevation to be 30° . Find the hight of the tree and breadth of the river.

Answer 1

Answer:

length of tree = 20√3m

breadth of river=20m

Step-by-step explanation:

as tan30 = y/(40+x)

   1/√3 = y/40+x

   y= (40+x)/√3   .........(1)

simmilarly

     tan 60 = y/x

      √3 =y/x

      y=√3 x          .............(2)

so put this value in 1

   3x = (40+ x)

   40-2x=0

 bredth of river= x=20

put it in 2

y=20√3