A vertical pole is divided by any point in the ratio 9:1. If both the segments subtend equal angles to each other at a point 20m away from the foot of the pole , find the height of the pole?

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Answer 1 · 2018-08-05T16:04:28

Let the lengths of two parts be #9xand x# m.

So total length will be #10x# m

So length of hypotenuse #=sqrt(20^2+100x^2)# m

As the angles subtended by two parts at 20 m distance from the foot are same, we can write

#sqrt(20^2+100x^2)/20=9/1#

#=>(20^2+100x^2)/400=81#

#=>100x^2=81xx400-400=80xx400#

#=>x=sqrt320=8sqrt5#

So length of the pole #=80sqrt5# m