Answer:
13
Step-by-step explanation:
Since this is a right triangle, we can use the Pythagorean theorem
a^2 + b^2 = c^2
where a and b are the legs and c is the hypotenuse
12^2 + 5^2 = c^2
144 + 25 = c^2
169 = c^2
Taking the square root of each side
sqrt(169) = sqrt(c^2)
13 = c