# A T.V. tower stands vertically on a bank of a river. From a point on the other bank directly opposite the tower, the angle of elevation of the top of the tower is 60°. From a point 20 m away this point on the same bank, the angle of elevation of the top of the tower is 30°. Find the height of the tower and the width of the river.

Let BC be the height of the T.V tower and AB be the width of the river.

In ∆ABC,

tan 60° =

√3 = ------(1)

In ∆ABC,

tan 30° =

tan 30° =

=

√3h = 20+ ---------(2)

On substituting value of h in eqn.(2)

√3× √3 = 20+

3

3

2

On substituting value of in eqn. (1)

h = √3

h = 10√3 m.

Therefore height of T.V tower is 10√3 m. and width of river is 10 m.

Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
Related Videos
Trick to learn all Trigonometric Formulae28 mins
Champ Quiz | Trigger on Trigonometry47 mins
Fundas of Trigonometry50 mins
Champ Quiz | Trigonometry Important Questions33 mins
NCERT | Trigonometric Identities52 mins
Champ Quiz | NTSE Trigonometry50 mins
Testing the T- Ratios of Specified Angles57 mins
Foundation | Cracking Previous Year IMO QuestionsFREE Class
Basic Concept of Trigonometry43 mins
NCERT | Imp. Qs. on Trigonometry42 mins
Try our Mini CourseMaster Important Topics in 7 DaysLearn from IITians, NITians, Doctors & Academic Experts
Dedicated counsellor for each student
24X7 Doubt Resolution
Daily Report Card
Detailed Performance Evaluation
view all courses