Geometry

Question Analysis:
This evaluates indirect proof application in geometry.

Key Concept Explanation:
Triangle Angle Sum Theorem: States the sum of angles in a triangle is 180°.

Step-by-Step Solution:
Assume: A triangle has two right angles (90° each).
Calculate Third Angle: 90° + 90° + x = 180° ⇒ x = 0°.
Contradiction: An angle of 0° violates the definition of a triangle.

Option Analysis:
B) Correct: The angle sum would technically be 180°, but the third angle va...