Question

a person standing on the bank of a river observes that the angle of elevation of the top of a tree standing on opposite bank is 60 degree when he moves 30 metre away from the bank he finds the angle of elevation to be 30 degree find the height of the tree and width of the river​

Answer 1

Step-by-step explanation:

Let height of tree = h

and width of bank = a

In first case,

tan60° = h/a

√3=h/a

h=√3a ....(1)

In second case,

tan30°= h/a+30

1/√3 = h/a+30

(cross multiplication)

√3h = a+30

3a = a+30. {from (1)}

hence, a = 15m

from (1)

h = 1.732 × 15. (a=15 , √3=1.732)

h = 25.9m. answer~~

$\frac{h}{x}$