(浙江专用)2018版高考数学大一轮复习高考专题突破五高考中的立体几何问题教师用书INCLUDEPICTURE"E:\\师阁\\2017\\一轮\\一轮数学(浙江)\\word\\考点自测.TIF"\*MERGEFORMATINETINCLUDEPICTURE"E:\\师阁\\2017\\一轮\\一轮数学(浙江)\\word\\考点自测.TIF"\*MERGEFORMATINETINCLUDEPICTURE"E:\\师阁\\2017\\一轮\\一轮数学(浙江)\\word\\考点自测.TIF"\*MERGEFORMATINETINCLUDEPICTURE"\\\\师阁\\e\\师阁\\2017\\一轮\\一轮数学(浙江)\\word\\考点自测.TIF"\*MERGEFORMATINET1.多面体的三视图如图所示,则该多面体的体积为()INCLUDEPICTURE"E:\\师阁\\2017\\一轮\\一轮数学(浙江)\\word\\Z49.TIF"\*MERGEFORMATINETINCLUDEPICTURE"E:\\师阁\\2017\\一轮\\一轮数学(浙江)\\word\\Z49.TIF"\*MERGEFORMATINETINCLUDEPICTURE"E:\\师阁\\2017\\一轮\\一轮数学(浙江)\\word\\Z49.TIF"\*MERGEFORMATINETINCLUDEPICTURE"\\\\师阁\\e\\师阁\\2017\\一轮\\一轮数学(浙江)\\word\\Z49.TIF"\*MERGEFORMATINETA.B.2C.D.答案D解析由三视图可知该几何体为一个三棱柱削去一个三棱锥得到的几何体,该三棱柱的体积为×2×2×2=4,三棱锥的体积为××2×2×1=,所以该几何体的体积为4-=,故选D.2.正三棱柱ABC-A1B1C1中,D为BC中点,E为A1C1中点,则DE与平面A1B1BA的位置关系为()A.相交B.平行C.垂直相交D.不确定答案B解析如图取B1C1中点为F,连接EF,DF,DE,INCLUDEPICTURE"E:\\师阁\\2017\\一轮\\一轮数学(浙江)\\word\\8-196.TIF"\*MERGEFORMATINETINCLUDEPICTURE"E:\\师阁\\2017\\一轮\\一轮数学(浙江)\\word\\8-196.TIF"\*MERGEFORMATINETINCLUDEPICTURE"E:\\师阁\\2017\\一轮\\一轮数学(浙江)\\word\\8-196.TIF"\*MERGEFORMATINETINCLUDEPICTURE"\\\\师阁\\e\\师阁\\2017\\一轮\\一轮数学(浙江)\\word\\8-196.TIF"\*MERGEFORMATINET1则EF∥A1B1,DF∥B1B,∴平面EFD∥平面A1B1BA,∴DE∥平面A1B1BA.3.(2016·沈阳模拟)设α,β,γ是三个平面,a,b是两条不同直线,有下列三个条件:①a∥γ,b⊂β;②a∥γ,b∥β;③b∥β,a⊂γ.如果命题“α∩β=a,b⊂γ,且________,则a∥b”为真命题,则可以在横线处填入的条件是________.(把所有正确的序号填上)答案①或③解析由线面平行的性质定理可知,①正确;当b∥β,a⊂γ时,a和b在同一平面内,且没有公共点,所以平行,③正确.故应填入的条件为①或③.4.在正四棱柱ABCD-A1B1C1D1中,AA1=2AB,则直线CD与平面BDC1所成角的正弦值等于________.答案解析以D为坐标原点,建立空间直角坐标系,如图,INCLUDEPICTURE"E:\\师阁\\2017\\一轮\\一轮数学(浙江)\\word\\8-187.TIF"\*MERGEFORMATINETINCLUDEPICTURE"E:\\师阁\\2017\\一轮\\一轮数学(浙江)\\word\\8-187.TIF"\*MERGEFORMATINETINCLUDEPICTURE"E:\\师阁\\2017\\一轮\\一轮数学(浙江)\\word\\8-187.TIF"\*MERGEFORMATINETINCLUDEPICTURE"\\\\师阁\\e\\师阁\\2017\\一轮\\一轮数学(浙江)\\word\\8-187.TIF"\*MERGEFORMATINET设AA1=2AB=2,则D(0,0,0),C(0,1,0),B(1,1,0),C1(0,1,2),则DC=(0,1,0),DB=(1,1,0),DC1=(0,1,2).设平面BDC1的法向量为n=(x,y,z),则n⊥DB,n⊥DC1,则令y=-2,得平面BDC1的一个法向量为n=(2,-2,1).设CD与平面BDC1所成的角为θ,则sinθ=|cos〈n,DC〉|==.INCLUDEPICTURE"E:\\师阁\\2017\\一轮\\一轮数学(浙江)\\word\\题型分类深度剖析.TIF"\*MERGEFORMATINETINCLUDEPICTURE"E:\\师阁\\2017\\一轮\\一轮数学(浙江)\\word\\题型分类深度剖析.TIF"\*MERGEFORMATINETINCLUDEPICTURE"E:\\师阁\\2017\\一轮\\一轮数学(浙江)\\word\\题型分类深度剖析.TIF"\*MERGEFORMATINETINCLUDEPICTURE"\\\\师阁\\e\\师阁\\2017\\一轮\\一轮数学(浙江)\\word\\题型分类深度剖析.TIF"\*MERGEFORMATINET2题型一求空间几何体的表面积与体积例1(2016·全国甲卷)如图,菱形ABCD的对角线AC与BD交于点O,点E,F分别在AD,CD上,AE=CF,EF交BD于点H,将△DEF沿EF折到△D′EF的位置.INCLUDEPICTURE"E:\\师阁\...