Answer:
The hypotenuse of the triangle measures 13 inches.
Explanation:
Since the Pythagorean theorem states that in any right triangle the lengths of the three sides are related by the equation A ^ 2 + B ^ 2 = C ^ 2, to determine the length of the hypotenuse in a right thangle with legs 5 inches and 12 inches the following calculation should be performed: 
 
5 ^ 2 + 12 ^ 2 = X ^ 2 
25 + 144 = X ^ 2 
√169 = X 
13 = X 
 
Therefore, the hypotenuse of the triangle measures 13 inches.