Geometry

Question Analysis:
This problem asks what additional condition is required to apply HL Theorem for proving triangle congruence.

Key Concept Explanation:
The HL Theorem requires:
The triangles must be right triangles. ✅ (Given)
The hypotenuse and one leg must be congruent.

Step-by-Step Solution:
We are given that the triangles are right triangles and one leg is congruent.
To apply HL, we also need the hypotenuse to be congruent.

Option Analysis:
A (Incorrect): Knowing both legs are congruent proves SSS, not HL.
B (Correct): Congruent hypotenuses satisfy HL.
C (Incorrect): It satisfies ASA, not HL.
D ...