Geometry

Question Analysis:
This applies ASA to a practical scenario, testing both congruence and angle-sum understanding.

Key Concept Explanation:
ASA (A): Directly applies (two angles + included side).
Third Angle (D): Must be equal (180° − 50° − 60° = 70°).

Step-by-Step Solution:
Verify ASA conditions:
Two angles (50°, 60°) + included side (10 in) → ASA holds (A).
Evaluate other options:
(B) AAS: Not applicable (no non-included side given).
(C) Similarity: True, but congruence is stronger (so "not necessarily" is false).
(D) Third angle: Must be 70° in both → True.

Common Mistakes:
Choosing AAS (B): No side is non-included here.
Selecting C: ASA ensures congruence, not just similarity.

Summary:...