摘要:2.(全国Ⅱ•理•7题)已知正三棱柱ABC-A1B1C1的侧棱长与底面边长相等.则AB1与侧面ACC1A1所成角的正弦等于( A ) A. B. C. D.
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(1)求证C1E∥平面A1BD;
(2)求证AB1⊥平面A1BD;
(3)求三棱锥A1-C1DE的体积. 查看习题详情和答案>>
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