Geometry

Question Analysis:
This question tests the definition of angle congruency.

Key Concept Explanation:
Congruent angles must have equal measures, regardless of their orientation or position.
Type (acute, right) or shared vertices are irrelevant to congruency.

Step-by-Step Solution:
Option A: Incorrect. Acute angles are not necessarily congruent.
Option B: Correct. Angle measures determine congruency.
Option C: Incorrect. Shared vertices don’t guarantee equal measures.
Option D: Incorrect. All right angles are congruent, but this is a specific case, not the general rule.

Common Mistakes:
Choosing D be...