Question

Two poles of height $6m$ and $11m$ stand on a plane ground of the distance between their feet $12m$, find the distance between their tops.

• A. $12cm$
• B. $13cm$
• C. $26cm$
• D. $14cm$

Answer 1

The correct option is B

$13cm$

Explaination for the correct answer:

Making a figure according to the given question.

Suppose AB and CD are two poles of $11m$ and $6m$ respectively.

We have to find the distance between B and D.

Let the distance BD be $xcm$

Join ED, such that $∆BED$ is a right angle triangle.

Now, applying Pythagoras theorem, we have;

$$\begin{gathered} Hypotenus{e}^2=Perpendicula{r}^2+Bas{e}^2 \\ \Rightarrow B{D}^2=B{E}^2+E{D}^2 \\ \Rightarrow x^2=5^2+{12}^2 \\ \Rightarrow x^2=25+144 \\ \Rightarrow x^2=169 \\ \Rightarrow x=\sqrt{169} \\ \Rightarrow x=13 \end{gathered}$$

Hence, the distance between the tops of two poles is $13cm$

Therefore, option B is correct.