The proof that ΔRST ≅ ΔVST is shown. Given: ST is the perpendicular bisector of RV. Prove: ΔRST ≅ ΔVST Triangle R S V is cut by perpendicular bisector S T. Point T is the midpoint of line segment R V. What is the missing reason in the proof? Statements Reasons 1. ST is the perpendicular bisector of RV. 1. given 2. ∠STR and ∠STV are right angles. 2. def. of perpendicular bisector 3. RS ≅ VS 3. ? 4. ST ≅ ST 4. reflexive property 5. ΔRST ≅ ΔVST 5. HL theorem perpendicular bisector theorem converse of the perpendicular bisector theorem Pythagorean theorem SSS congruence theorem