解:如图建立空间直角坐标系…(1分)(1)由题意可得:A1(2,0,2),B1(0,0,2),C(0,2,0),C1(0,2,2)所以 A1C =(?2,2,?2), A1B1 =(?2,0,0), CC1 =(0,0,2)设平面A1CB1的法向量为 n =(x1,y1,z1),平面A1CC1的法向量为 m =(x2,y2,z2)则有 A1C