---- Excuse me, could you please tell me the way to the nearest hospital?

                          ---- I'm sorry,      _I am new here. You can ask the policeman over there.

如图，四边形ABCD为矩形，E是BC延长线上一点，AE交CD于点G，F是AE上一点，并且AC=CF=EF，∠AEB=15°．

（1）求∠ACF的度数；

（2）证明：矩形ABCD为正方形．