lordphone
2020-06-29T01:37:15+00:00
如图,三棱锥P-ABC中,PA垂直AB,AB垂直BC,M、N分别为AC、PC中点,且三角形PMC为正三角形。
求证:面PAB垂直面PBC
[img]https://img.nga.178.com/attachments/mon_202007/07/-7Q5-bzrfZ1oT3cSqo-zk.jpg.medium.jpg[/img]
求证:面PAB垂直面PBC
[img]https://img.nga.178.com/attachments/mon_202007/07/-7Q5-bzrfZ1oT3cSqo-zk.jpg.medium.jpg[/img]