Question 657339
You have a right triangle, therefore you can use the Pythagorean Theorem.

This states that for legs a,b and hypotenuse c, you have:

{{{a^2 + b^2 = c^2}}}

Using this we have

{{{(5)^2 + (12)^2 = c^2}}}
{{{25 + 144 = c^2}}}
{{{169 = c^2}}}
{{{ c = 13 }}} or {{{c = -13}}}
But since we're talking about a length, c can only be positive.

Thus c =13.