Question

Length of wire connecting the top of two poles of height 20m and 14m and making 30 degrees with horizontal is ___.

• A. 8 m
• B. 10 m
• C. 14 m
• D. 12 m

Answer 1

The correct option is D 12 m

Let distance between two poles be $x$ and the length of the wire be $y$.

$\tan \left({30}^{\circ }\right)=\frac{20-14}{x}=\frac{6}{x}$

$\frac{1}{\sqrt{3}}=\frac{6}{x}$

$\Rightarrow x=6\sqrt{3}$

As length of the wire will form the hypotenuse of right angled triangle thus formed,

$y^2=6^2+(6\sqrt{3}{)}^2=144$

$\therefore y=12\text{m}$