Banner 0
Banner 1
Banner 2
Banner 3
Banner 4
Banner 5
Banner 6
Banner 7
Banner 8
Banner 9

Q.

A building subtends a right angle at the top of a pole on the other side of the road. The line joining the top of the pole and the top of the building makes an angle of 60°  with the vertical. If the width of the road is 45 m, then what will be the height of the building?


see full answer

Your Exam Success, Personally Taken Care Of

1:1 expert mentors customize learning to your strength and weaknesses – so you score higher in school , IIT JEE and NEET entrance exams.
An Intiative by Sri Chaitanya

a

30 3  m

b

60 3  m

c

60 2  m

d

30 2  m 

answer is B.

(Unlock A.I Detailed Solution for FREE)

Best Courses for You

JEE

JEE

NEET

NEET

Foundation JEE

Foundation JEE

Foundation NEET

Foundation NEET

CBSE

CBSE

Detailed Solution

Given that,
A building suspends a right angle at the pole on the other side of the road
We draw a diagram,
Question ImageWe use tanθ= height base   in the triangle BED,
tan 30 ° = BE DE BE=DE×tan 30 °   Substituting the value DE=45  and using tan30°= 1 3  ,
BE= 45 3   ……(1)
 We use the tangent of an angle in the triangle AED,
tan 60 = AE DE AE=DE×tan 60   Substituting the value DE=45  and tan60°= 3  ,
AE=45 3  ……(2)
Now we add the equation (1) and (2),
BE+AE= 45 3 +45 3 AB= 45+45×3 3 AB= 180 3 AB=60 3 m   Thus the height of the building will be 60 3   m.
Therefore the correct option is 2.
 
Watch 3-min video & get full concept clarity
score_test_img

courses

No courses found

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Get Expert Academic Guidance – Connect with a Counselor Today!

best study material, now at your finger tips!

  • promsvg

    live classes

  • promsvg

    progress tracking

  • promsvg

    24x7 mentored guidance

  • promsvg

    study plan analysis

download the app

gplay
mentor

Download the App

gplay
whats app icon
personalised 1:1 online tutoring