如图,三棱柱ABC-A1B1C1中,侧棱AA1⊥底面ABC,△ABC是边长为2的正三角形,点P在A1B上,

问题描述:

如图,三棱柱ABC-A1B1C1中,侧棱AA1⊥底面ABC,△ABC是边长为2的正三角形,点P在A1B上,
且AB⊥CP.
证明 1.P为A1B中点.
2.若A1B⊥AC1,求三棱锥P-A1AC的体积.

1.取AB中点M,连接CM,PMAB⊥CPAB⊥CMAB⊥平面CPMAB⊥PMPM//AA1,M为AB中点 所以P为A1B中点2.取A1B1中点N,连接AN,C1NA1B⊥AC1C1N⊥A1BA1B⊥平面AC1NA1B⊥AN △NA1A与△A1AB相似AB=2 AA1=√2点P到平面A1AC的距离d等于点B...