Answer:
39 ft
Step-by-step explanation:
Using the description as a guideline I have drawn out the situation (badly drawn) as seen in the picture below. From the picture, we see that we need to find x which is the length of one of the ropes. Once we have this length we simply multiply it by 3 to find out how much rope we need altogether. Since this is the diagonal of a triangle we can use the Pythagorean theorem to solve for x.
Pythagorean theorem: [tex]a^{2} +b^{2} = c^{2}[/tex] .... which a and b are the two sides while x is the diagonal.
[tex]5^{2} +12^{2} = x^{2}[/tex]
[tex]25 + 144 = x^{2}[/tex]
[tex]169 = x^{2}[/tex] ... now we square root both sides
[tex]13 = x[/tex]
Now that we have the length of one of the ropes we simply multiply this by 3 to find the total amount of rope needed.
13 * 3 = 39 ft
