不妨设棱长为2
由BD垂直于AC,BD垂直于A1A得BD垂直于面A1AC,从而BD垂直于A1O.
A1G^2=A1C1^2+C1G^2=9
A1O^2=A1A^2+AO^2=6
OG^2=OC^2+CG^2=3由勾股定理得OG垂直于A1O
综上所述,A1O垂直与平面GDB.
不妨设棱长为2
由BD垂直于AC,BD垂直于A1A得BD垂直于面A1AC,从而BD垂直于A1O.
A1G^2=A1C1^2+C1G^2=9
A1O^2=A1A^2+AO^2=6
OG^2=OC^2+CG^2=3由勾股定理得OG垂直于A1O
综上所述,A1O垂直与平面GDB.