Question

Which statement is not always true for a parallelogram?

A. Consecutive angles are supplementary.
B. Diagonals are congruent.
C. Opposite sides are congruent.
D. Opposite angles are congruent.

Answer 1

Answer: B. Diagonals are congruent.

Step-by-step explanation:

If the diagonals are congruent, then we'd have a rectangle. Any rectangle is a parallelogram, but not the other way around.

If we had a non-rectangular parallelogram, with none of the angles 90 degrees, then the diagonals will not be the same length.

Choices A, C and D are true for any parallelogram (rectangle or not).