They would be congruent by the side side side (s-s-s) theorem. They are BOTH right triangles. You have one triangle with legs = 5 and 12, by the Pythagorean Theorem, the hypotenuse would be 13. In the other triangle, you have a leg = 12 and hypotenuse = 13. By the Pythagorean Theorem, the other leg would be 5. So, you have 2 triangles with sides of 5, 12 and 13 and they are congruent by the (s-s-s) theorem.
