JEE Class main Answered
The angle of elevation of the top of a vertical tower from a point A, due east of it is 45°. The angle of elevation of the top of the same tower from a point B, due south of A is 30°. If the distance between A and B is 54√2 m , then the height of the tower (in metres), is :
a) 36/√3 b) 54
c) 54/√3 d) 108
Asked by Ranjeetgupta26068 | 16 May, 2019, 00:11: AM
![](https://images.topperlearning.com/topper/tinymce/imagemanager/files/cc8d0c5b9139abab6ade6794161bf42b5cde33d68229e2.66495860Picture1.png)
![AB space equals 54 square root of 2
also space using space pythgoras space we space get
straight y squared equals straight x squared plus open parentheses 54 square root of 2 close parentheses squared ____ open parentheses 1 close parentheses
angle DAO space equals space 45 degree
tan space 45 space equals space straight h over straight x
straight h equals x____ open parentheses 2 close parentheses
angle DBO space equals space 30 degree
tan space 30 space equals space straight h over straight y
square root of 3 straight h equals y____ open parentheses 3 close parentheses
sub space open parentheses 2 close parentheses & open parentheses 3 close parentheses space in space open parentheses 1 close parentheses
we space get space
open parentheses square root of 3 straight h close parentheses squared equals open parentheses straight h close parentheses squared plus open parentheses 54 square root of 2 close parentheses squared
straight h equals space 54 straight m](https://images.topperlearning.com/topper/tinymce/cache/281135dd28fae3d07b9d65d55e19be22.png)
Answered by Arun | 17 May, 2019, 09:45: AM
JEE main - Maths
Asked by Ranjeetgupta26068 | 16 May, 2019, 00:11: AM