Răspuns:
Explicație pas cu pas:
Observam ca:
AB²=54
AC²=162
BC²=216
BC²=AB²+AC²⇒ ΔABC dreptunghic in A
Cum BC=2AB⇒m(∡C)=30°
m∡((MAB),(MBC))=m(∡ABC)=60°
MB⊥AB
MB⊥BC
AB⊂(MBA)
BC⊂(MBC)
MA=6√3
∡((MAC),(ABC))=∡MAB
BA⊥AC
BA⊂(ABC)
AC⊂(MAC)
In ΔMAB aplicam Pitagora
MA²=MB²+AB²
108=MB²+54
MB=3√6=AB⇒ m(∡MAB)=45°