Geometry

Question Analysis:
This question assesses understanding of opposite side congruence in parallelograms.

Key Concept Explanation:
In a parallelogram:
Opposite sides are equal in length

Step-by-Step Solution:
Given:
EF = 8 cm (opposite to GH).
FG = 5 cm (opposite to EH).
By definition, EH = FG = 5 cm.

Common Mistakes:
Misidentifying which sides are opposite.
Incorrectly assuming adjacent sides are equal (only true in rhombuses).

Summary:
The problem directly applies the property that op...