Exercise 67 Page 657

• Both pairs of opposite sides are parallel.
• Both pairs of opposite sides are congruent.
• Both pairs of opposite angles are congruent.
• The diagonals bisect each other.
• A pair of opposite sides is both parallel and congruent.

Let's analyze the given quadrilateral.

Looking at the marks in the diagram, we notice that only one pair of opposite sides is congruent and only one pair of opposite sides that is parallel. Remember that for it to be a parallelogram, a pair of opposite sides must be congruent and parallel. Therefore, it is not a parallelogram. This quadrilateral could be an isosceles trapezoid, since its legs are congruent.