Geometry

Question Analysis:
This question involves analyzing overlapping triangles to determine whether they share a common side or a common angle.
The main focus is on visual recognition of shared geometric elements—especially sides and angles—between two adjacent triangles.

Key Concept Explanation:
Shared side: A line segment that is part of both triangles
Shared angle: An angle that has the same vertex and same two rays in both triangles
Shared vertex only does not mean shared angle

Step-by-Step Solution:
Segment JK:
Present in both △MJK and △LJK → ✅ Shared side
Angle ∠MJK:
Belongs only to △MJK → ❌ Not shared
Segment LK:
Belongs only to △LJK → ❌ Not shared
Angle ∠MKJ:
Appears only in △MJK → ❌ Not shared

Common Mistakes:
Confusing shared vertex with shared angle:
Students might think that because both triangles have vertex K, an...