The horizontal distance between two towers is 150 m. The angle of depression of the top of one tower as observed from the top of other tower, which is 120 m in
height, is 30°. Find the height of the first tower.
Answers
Answered by
5
see the given figure
Horizontal distance between two towers = 150m
let the height of first tower be x m
ED = 120 m
but ED = BC = 120
AC = 120 m
AB = AC - BC
AB = (x - 120)m
Now , in ∆ABE
tanA = perpendicular/base = AB/BE
tan30° = (x - 120)/150
1/√3 = (x - 120)/150
(x - 120)√3 = 150
x√3 - 120√3 = 150
x√3 = 120√3 + 150
x√3 = 30(4√3 + 5)
x = {30(4√3 + 5)}/√3
rationalise √3
x = {30(4√3 + 5)√3} / √3.√3
x = {30 × √3(4√3 + 5)} / 3
x = 10√3(4√3 + 5)
x = (120 + 50√3)
or
x = 10(12 + 5√3)
Hence, the height of tower is 10(12 + 5√3)m
Attachments:
Answered by
7
Ur answer is 33.4 m!!
Mark me as brainliest if you think my answer is helpful
Attachments:
Similar questions