In ΔABC and ΔDEF, AB = DE, AB || DE, BC = EF and BC || EF. Vertices A, B, and C are joined to vertices D, E and F respectively ( see the given figure).
AC||DF
AC=DF
As ACFD is a parallelogram, therefore, the pair of opposite sides will be equal and parallel to each other.
∴ AC || DF and AC = DF.