Q. 20

If a 1.5 m tall girl stands at a distance of 3 m from a lamp-post and casts a shadow of length 4.5 m on the ground, then the height of the lamp-post is
A. 1.5 m

B. 2 m

C. 2.5 m

D. 2.8 m

Answer :


Let AB be the tower of h meters and CD be the girl of 1.6m height casting shadow = DE of 4.8 m, standing at the distance of 3.2m from the tower.


In Δ CDE


tan CED = CD/ DE = ………………….1


tan CED = 1/3


In Δ ABE


tan CED = = ………………….2


From 1 and 2


=


h = m


h = 2.5m

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
NCERT | Trigonometric Identities52 mins
Champ Quiz | Trigonometry Important Questions33 mins
Champ Quiz | NTSE Trigonometry50 mins
Testing the T- Ratios of Specified Angles57 mins
Foundation | Cracking Previous Year IMO QuestionsFREE Class
NCERT | Imp. Qs. on Trigonometry42 mins
Quiz | Trail of Mixed Questions on Trigonometry59 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