Heights and Distances Practice Test 1

Question : 5 of 40

Marks: +1, -0

The angle of elevation of a balloon from twoconsecutive kilometer stones in its same sideis 60° and 30° respectively. Then the height ofthe balloon in km is:

$√3 / 2$
$1/2$
$√3/4$
$1 / 3$

Validate

Solution:

In ΔBDC,

\tan 30°={BD}/{BC}

1/√3=x/a

x=a/√3

......(i)
In ΔABC,

\tan60°={AB}/{BC}

√3={x+1}/a

x=√3a-1

......(ii)
From (i) and (ii) we get

a/√3=√3a-1

a=√3/1\kms

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