Which set of three numbers could represent the lengths of the sides of a right triangle?
7, 9, 11
8, 15, 17
10, 15, 20
12, 18, 22

The Converse to the Pythagorean Theorem states that: If a^2 + b^2 = c^2, then the triangle is a right triangle.

7^2 + 9^2 ??=?? 11^2
49 + 81 ??=?? 121
130 ??=?? 122 NO

8^2 + 15^2 ??=?? 17^2
64 + 225 ??=?? 289
289 ??=?? 289 YES

10^2 + 15^2 ??=?? 20^2
100 + 225 ??=?? 400
325 ??=?? 400 NO

12^2 + 18^2 ??=?? 22^2
144 + 324 ??=?? 484
468 ??=?? 484 NO

8,15,17 is the only set that makes a right triangle