Heights and Distances Practice Test 2

Question : 21 of 24

Marks: +1, -0

Two poles of equal heights stand on eithersides of a roadway which is 100 m wide. At apoint on the roadway between the pole, theelevation of the tops of the poles are 60° and45°. Find the height of the poles.

${50√3}/{1+√3}$
${100√3}/{1+√3}$
${40√3}/{1+√3}$
All of the above
None of these

Validate

Solution:

In ΔECD,

{ED}/{CD}=\tan45°⇒h/y=1

⇒h=y

......(1)
In ΔABC,

{AB}/{BC}=\tan60°

h/{100-y}=√3

h=√3(100-y)

......(2)
From equations (1) and (2),

y=100√3-√3y

⇒y={100√3}/{1-√3}

∴h = y={100√3}/{1-√3}

Go to Question:

Prev Question

Next Question