题目
题型:不详难度:来源:
EF |
AD |
BC |
答案
∴
GF |
1 |
2 |
AD |
EG |
1 |
2 |
BC |
又∵
GF |
EG |
EF |
∴
EF |
EG |
GF |
=
1 |
2 |
AD |
1 |
2 |
BC |
=
1 |
2 |
AD |
BC |
∴
EF |
AD |
BC |
核心考点
举一反三
1 |
3 |
1 |
3 |
(1)求证:GE
题型:平面PAC;
(2)求证:GF⊥平面PBC.
(2)求证:GF⊥平面PBC.
(1)求证:DM∥平面APC;
(2)求证:平面ABC⊥平面APC.
(1)PA∥平面BDE;
(2)平面EBD⊥平面PAC;
(3)若PA=AB=4,求四棱锥P-ABCD的全面积.
(Ⅰ)求证:EF∥平面CB1D1;
(Ⅱ)求证:平面CAA1C1⊥平面CB1D1.