ALMOST 20 POINTS Why is it incorrect to classify the polygon shown as a parallelogram?

A. It has four sides.
B. Some sides are shorter than others.
C. It has only one pair of parallel sides.
D. All the interior angles have different measures.

The perimeter of ? cde is 55 cm. a rhombus dmfn is inscribed in this triangle so that vertices m, f, and n lie on the sides cd , ce , and de respectively. find cd and de if cf=8 cm and ef=12 cm. the answer is not cd=20 and de=15. i have tried that one, it does not work.