证明:连结AC交BD于O、连结EO,
∵E、O是PC、AC中点,∴EO∥PA,
∵EO在平面BDE中,∴PA∥平面BDE,证毕.
P为正方形ABCD所在平面外一点,且P到正方形的四顶点的距离相等,E为PC中点,求证:PA∥平面BDE
P为正方形ABCD所在平面外一点,且P到正方形的四顶点的距离相等,E为PC中点,求证:PA∥平面BDE
数学人气:862 ℃时间:2019-11-04 13:13:34
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