Anthony decided to buy two dvds that were not included in the deal. his
price after tax was $21.60. what was the cost of the two dvds before the
sales tax was added?
3 for $22.50 5 for $37.50

Given: ae ≅ ce ; de ≅ be prove: abcd is a parallelogram. we have that ab || dc. by a similar argument used to prove that △aeb ≅ △ced, we can show that △ ≅ △ceb by. so, ∠cad ≅ ∠ by cpctc. therefore, ad || bc by the converse of the theorem. since both pair of opposite sides are parallel, quadrilateral abcd is a parallelogram.