Geometry

Question Analysis：
This question connects reflection principles to polygon symmetry, testing geometric pattern recognition.

Key Concept Explanation：
Regular pentagon has central angles of 72°
Reflection lines bisect these angles → 36° between adjacent mirrors
Five reflection symmetries correspond to dihedral group D₅

Step-by-Step Solution：
Calculate central angle: 360°/5 = 72°
Adjacent mirrors intersect at half central angle: 72°/2 = 36°
Verify: 2 × 36° = 72° matches rotation symmetry

Common Mistakes：
Confusing mirror angle with central angl...