Answer: SR ≅ UT
Step-by-step explanation:
Process of elimination:
1) RT ≅ TR doesn't help because RT and TR are the same line.
2) RU ⊥ TU doesn't help prove that ΔRST ≅ ΔTUR. It only proves that ∠TUR is a right angle (which is already given).
3) SR ⊥ ST also doesn't help prove that ΔRST ≅ ΔTUR. It only proves that ∠RST is a right angle (which is already given).
4) The statement that SR ≅ UT tells us that ΔRST and ΔTUR are right triangles and have a hypotenuse and leg in common (both triangles share a hypotenuse, RT, both triangles have a 90 degree angle, and SR ≅ UT). If SR ≅ UT, we can prove ΔRST ≅ ΔTUR by using the HL triangle congruence theorem.
