A conjecture and the flowchart proof used to prove the conjecture are shown. Given: S is the midpoint of segment R T. Segment U S is congruent to segment R S. Prove: Triangle S T U is an isosceles triangle. Art: An isosceles triangle S U T with base U T and a ray S R. Angle R S T measures 180 degrees. Lengths of S R and S T are equal. Lengths of S T and S U are equal. Drag an expression or phrase to each box to complete the proof.