Geometry

Question Analysis:
Focuses on applying congruency to side lengths.

Key Concept Explanation:
Corresponding sides are equal in length.

Step-by-Step Solution:
AB ≅ DE → DE = AB = 5 cm.

Option Analysis:
C is correct; others refer to non-corresponding sides.

Common Mistakes:
Confusing which sides correspond.

Summary：
For congruent triangles, corresponding sides have equal lengths.

Problem-Solving Tips:
Use the naming o...