1.BD⊥AC,BD⊥CC1BD⊥平面ACC1,AC1在平面ACC1内,所以BD⊥AC1,同理AC1⊥A1B,所以 AC1⊥平面A1BD2.设BD中点为O,连接A1O和EO,A1B=A1D,所以A1O⊥BD,EB=ED,所以EO⊥BD,所以∠A1EO为二面角A1-BD-E的平面角设正方体棱长为2,...