You bake cookies for a bake sale. The ratio of chocolate chip cookies to oatmeal cookies is 7 : 5. You bake 15 oatmeal cookies. How many chocolate chip cookies do you bake?

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.