# Question #6836c

Nov 6, 2017

What you have described here is a $3 , 4 , 5$ right $\angle \triangle$, so the guy wire is $30 f t$

#### Explanation:

The $3 , 4 , 5$ right $\angle \triangle$ will keep popping up in your mathematical career, so it is one you should memorize.

This is an example of the Pythagorean theorem as described here:
https://en.wikipedia.org/wiki/Pythagorean_theorem

So our cable length $L$ is found by: ${L}^{2} = {18}^{2} + {24}^{2}$

${L}^{2} = 324 + 576$

${L}^{2} = 900$

$L = 30$, and since all distances are given in $f t$, $L = 30 f t$

But, if we divide all the distances by $6$;

we arrive at the $3 , 4 , 5$ right $\angle \triangle$,

so the answer could be found without so much math.