Which measurements represent the side lengths of a right triangle?

9 in, 12 in, 15 in
9 in, 12 in, 15 in

2 in, 7 in, 9 in
2 in, 7 in, 9 in

10 in, 12 in, 20 in
10 in, 12 in, 20 in

3 in, 4 in, 8 in