The lengths of two sides of a triangle are 5 and 12. what is the length of the hypotenuse?
work out the problem.

Well the hypotenuse is the longest length, which is always c, so we know that 5 and 12 have to be a and b 

a^2 + b^2 = c^2
5^2 + 12^2 = c^2
You slove the exponents and get:
25 + 144 = c^2
Add.
169 = c^2
Sqaure root each sides
13 = c

So the hypotenuse is 13.

Good luck!