Contact us
Choose a category below so we can get back to you as quickly as possible.
L垂直AB且L垂直AC,即L垂直平面ABC,故L垂直於ABC中任意一條直線,BC屬於平面ABC故L垂直BC
We and our partners use cookies and other technologies to analyze traffic and optimize your experience. View more info and control your cookies settings at any time in our Cookies Policy.