Geometry

Question Analysis
This question involves identifying the incorrect biconditional statement.
The main focus is on verifying the logical validity of each statement.

Key Concept Explanation:
A biconditional statement requires both the original statement and its converse to be true, linked by "if and only if."
If either part is false, the biconditional statement is incorrect.

Step-by-Step Solution:
Analyze each option to determine if both the original statement and its converse are true.

Option A:
Original: If a point lies on the perpendicular bisector of a segment, then it is equidistant from the endpoints. (True)
Converse: If a point is equidistant from the endpoints of a segment, then it lies on the perpendicular bisector. (True)
This is a valid biconditional statement.

Option B:
Original: If a quadrilateral is a parallelogram, then opposite sides are equal and parallel. (True)
Converse: If a quadrilateral has opposite sides equal and parallel, then it is a parallelogram. (True)
This is a valid biconditional statement.

Option C:
Original: If an angle is acute, then it measures exactly 90°. (False, acute angles measure less than 90°)
Converse: If an an...