Question

diagonals bisect each other
diagonals are congruent
both pairs of opposite angles are congruent
both pairs of opposite sides are parallel
which is not a property of a parallelogram?

Explanation:

Step1: Recall properties of parallelogram

In a parallelogram, opposite sides are parallel and congruent, opposite angles are congruent.

Step2: Analyze diagonal property

Diagonals of a parallelogram bisect each other, but in a general parallelogram (not a rectangle or square which are special cases of parallelograms), diagonals are not congruent.

Answer:

Diagonals are congruent