Problem
(1) Figure RST has been rotated \( 90^{\circ} \) clockwise to form figure \( O P Q \). Which of the following statements is true? (A) \( m \angle R \cong m \angle Q \) (B) \( m \angle S \cong m \angle P \) (C) \( \overline{R S} \cong \overline{P Q} \) (D) \( \overline{S T} \cong \overline{O P} \)
Solution
Step 1 ：Step 1: During rotation, angles remain congruent.
Step 2 ：Step 2: R is rotated to Q during the \( 90^{\circ} \) clockwise rotation.
Step 3 ：Step 3: \( m \angle R \cong m \angle Q \)
