Geometry

Question Analysis:
This problem is a textbook contradiction setup with figures and properties.
The main focus is identifying the assumption structure: hypothesis true, conclusion false.

Key Concept Explanation:
To prove “If p → q” by contradiction, assume p is true and q is false — then derive a contradiction.
In this case:
p: quadrilateral is a rectangle
q: diagonals are congruent
So for contradiction, assume: rectangle AND diagonals are not congruent

Step-by-Step Solution:
Assume quadrilateral is a rectangle
Also assume diagonals are not congruent
But by definition of rectangle (with right angles and opposite sides equal), diagonals must be equal
This leads to a contradiction → thus original statement is true

Option Analysis:
A. ❌ Square is a special case, doesn’t contradict
B. ✅ Thi...