15.) what is the converse of the congruent and parallel sides of a quadrilateral theorem.
a.) if a quadrilateral is not a parallelogram, then it does not have sides that are congruent
and parallel
b.) if a quadrilateral is a parallelogram, it has 4 congruent sides and 1 pair of parallel
sides.
c.) a quadrilateral is a parallelogram if and only if it has two sides that are congruent and
parallel
d.) if a quadrilateral is a parallelogram, then it has two sides that are congruent and
parallel