To prove that this a right triangle, just plug these numbers in the Pythagorean Theorem.
Let's assume the longest side is the hypotenuse.
Let's see if these two expressions are equal
a^2 + b^2 = c^2
32^2 + 60^2 = 68^2
1024 + 3600 = 4624
4624 = 4624
Since all these side lengths satisfy the Pythagorean Theorem, the statement must be true.
Have an awesome day! :)