A quadrilateral has a parallelogram if one pair of opposite sides is congruent and parallel. Parallelograms are designed to have diagonals that bisect one another. When ABCD is bisected by — BD and —AC, then ABCD is a parallelogram.
A quadrilateral has a parallelogram if one pair of opposite sides is coinciding exactly when superimposed and parallel. Parallelograms are designed to have diagonals that bisect one another. When abcd is bisected by bd and ac, then abcd is a parallelogram.