Geometry

Question Analysis:
This question targets proof by contradiction with a geometric configuration involving angle relationships.
The main focus is correctly applying the contradiction structure by keeping the hypothesis and negating the conclusion.

Key Concept Explanation:
In contradiction, you assume p is true and q is false (i.e., assume “p and not q”).
Statement: “If not parallel → angles not congruent”
So for contradiction: Assume lines not parallel AND angles are congruent.

Step-by-Step Solution:
Statement: If ¬parallel → ¬congruent
For contradiction: assume ¬parallel AND congruent
But this violates angle relationships in transversals
Contradiction arises → original statement must be true

Option Analysis:
A. ❌ This just restates the original
B. ❌ A...