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在四棱柱ABCD-A1B1C1D1中.AA1⊥平面ABCD.底面ABCD为菱形.∠BAD=
在四棱柱ABCD-A1B1C1D1中.AA1⊥平面ABCD.底面ABCD为菱形.∠BAD=
发布时间:2021-02-20 14:20:42
在四棱柱ABCD-A1B1C1D1中,AA1⊥平面ABCD,底面ABCD为菱形,∠BAD=60°,P为AB的中点,Q为CD1的中点.
(1)求证:DP⊥平面A1ABB1;
(2)求证:PQ∥平面ADD1A1.
网友回答
答案:
分析:
(1)利用菱形和等边三角形的性质、线面垂直的判定定理即可证明;
(2)利用三角形的中位线定理、平行四边形的性质、线面、面面平行的判定与性质定理即可证明.
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