Question

Ajutor ！！！！！！！！！！ peste 20 puncte

Answer 1

   
[tex]\bf\\ a)~~pr_\alpha B = C\\ b)~~pr_\alpha (AB) = (AC)\\ c)~~pr_\alpha (BC) = C~~~~deoarece~BC \perp \alpha\\ d)~~pr_{_{AC}} B = C\\ e)~~pr_{_{BC}} A = C\\ f)~~pr_\alpha (AC) = (AC)~~~deoarece~AC \subset \alpha \\ [/tex]