如图,已知BE平分∠ABD,DE平分∠BDC,并且∠1＋∠3＝90°,则__∥___理由是____________.

如图, 已知BE平分∠ABD, DE平分∠BDC, 并且∠1＋∠3＝90°, 则__∥___理由是____________.