Answer: D. No, a and b are interchangeable, and C is the longest side.
Explanation:
Either A and B which are the two legs can be greater than the hypotenuse which is C. They hypotenuse has to always be greater than the two legs and the two legs have the same lengths but it can't be greater than the hypotenuse.
For example let's say you have a right angle with side lengths 3,4 and 5.
5 in this case has to be always the hypotenuse.
A could be either 3 or 4 but not 5
And B could also be 3 or 4 but not 5
because A squared plus B squared is always equal to the hypotenuse which is 5.
3^2 + 4^2 = 5^2
9 + 16 = 25
25 = 25