(1/2)在直三棱柱ABC-A1B1C1,AC=5,BC=4,AB=5,AA1=4,点D是AB的中点,(1)求证:AC垂直BC:(...
(1/2)在直三棱柱ABC-A1B1C1,AC=5,BC=4,AB=5,AA1=4,点D是AB的中点,(1)求证:AC垂直BC:()求证
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