Geometry

Question Analysis:
This question uses the property that opposite sides in a rectangle are equal.
The main focus is solving an equation formed by side lengths.

Key Concept Explanation:
In a rectangle, opposite sides are congruent: AB = CD.

Step-by-Step Solution:
Set AB = CD:
x + 3 = 2x - 1
→ Subtract x: 3 = x - 1
→ x = 4

Common Mistakes:
Setting adjacent sid...