1 . 如图1是图2的三视图,在三棱锥B-ACD中,E,F分别是棱AB,AC的中点.
![](https://img.xkw.com/dksih/QBM/2018/10/9/2049765222801408/2056286728192000/STEM/796858f9029140cd9477efc51a23eb43.png?resizew=273)
(1)求证:BC//平面DEF;
(2)求三棱锥A-DEF的体积.
![](https://img.xkw.com/dksih/QBM/2018/10/9/2049765222801408/2056286728192000/STEM/796858f9029140cd9477efc51a23eb43.png?resizew=273)
(1)求证:BC//平面DEF;
(2)求三棱锥A-DEF的体积.
您最近一年使用:0次
2016-12-04更新
|
483次组卷
|
3卷引用:2016-2017学年江西吉安一中高二上段考一数学(理)试卷
2 . 三棱柱
的直观图及三视图(主视图和俯视图是正方形,左侧图是等腰直角三角形)如图,
为
的中点.
![](https://img.xkw.com/dksih/QBM/2012/2/13/1570734397030400/1570734402379776/STEM/61b324465c6b473a84a058c937b0dba9.png?resizew=196)
![](https://img.xkw.com/dksih/QBM/2012/2/13/1570734397030400/1570734402379776/STEM/4c713b4a92e74b87bb304917e04c6d1e.png?resizew=204)
(1)求证:
平面
;
(2)求证:
平面
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ede6a60cad0e0b58e1549fda6e085719.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1a9c6a736e6eac98a676fa3232db5a5.png)
![](https://img.xkw.com/dksih/QBM/2012/2/13/1570734397030400/1570734402379776/STEM/61b324465c6b473a84a058c937b0dba9.png?resizew=196)
![](https://img.xkw.com/dksih/QBM/2012/2/13/1570734397030400/1570734402379776/STEM/4c713b4a92e74b87bb304917e04c6d1e.png?resizew=204)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b0f31c75b24e9f46ac73118fde73d143.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/361ba681e1c611ef91f4374374062914.png)
(2)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/52e2a9dfb75f36fe375d1693add819dd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/361ba681e1c611ef91f4374374062914.png)
您最近一年使用:0次