Geometry

Question Analysis：
This question applies the property of congruent opposite sides in parallelograms to solve for a variable.
The main focus is setting up an equation using opposite sides and solving for x.

Key Concept Explanation:
In a parallelogram, opposite sides are congruent (PQ ≅ SR, PS ≅ QR).

Step-by-Step Solution：
Set PQ = SR: 3x + 2 = 5x - 8.
Solve for x: 2 + 8 = 5x - 3x → 10 = 2x → x = 5.
Substitute x = 5 into PQ: PQ = 3(5) + 2 = 17.

Common Mistakes...