Mrs. Baxter needs to buy new headphones for all 559 students. If each headphone costs 15 dollars, how much will it cost Mrs. Baxter to buy all the headphones? (ik its easy i just cant get the right answer somehow)

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.