Which of the following sequences is an arithmetic sequence? O {1,2,4,7,...)
O {1,3,9,27,...}
O {1,4,7,10,...}
O {1,-2.4,-8,...}

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.