Se consideră cubul ABCDEFGH, ACN BD {0}. EG A FH-
Demonstrați că
a) BD perpendicular (ACE);
b) AC perpendicular BH.
c) OQ paralel AE
d) OQ perpendicular (ABC)
![Se Consideră Cubul ABCDEFGH ACN BD 0 EG A FH Demonstrați Că A BD Perpendicular ACE B AC Perpendicular BH C OQ Paralel AEd OQ Perpendicular ABC class=](https://ro-static.z-dn.net/files/d9b/9c093250f5ee4b7efed7fa8ab9c78145.jpg)