Geometry

Question Analysis:
This question tests knowledge of triangle congruency properties.
The main focus is identifying the fundamental definition of congruent triangles.

Key Concept Explanation:
Congruent triangles are triangles that have:
Equal corresponding sides
Equal corresponding angles
Same area and perimeter
Same shape and size
These properties ensure that two congruent triangles are identical in all geometric aspects, even if they are rotated or reflected.

Step-by-Step Solution:
Review the definition of congruency:
Congruent triangles have the same size and shape.
Their corresponding angles and sides must be equal.

Option Analysis:
A) Incorrect – Angle equality alone does not ensure congruency; sides must also be equal.
B) Incorrect – Congruent triangles always have equal areas.
C) Correct – Definition of congruent triangles.
D) Incorrect – Different sizes mean similarity, not congruency.