[tex]\displaystyle Aflam~AC~folosind~teorema~cosinusului: \\ AC^2=AB^2+BC^2-2AB\cdot BC\cdot\cos(B) \\ AC=\sqrt{AB^2+BC^2-2AB\cdot BC\cdot\cos(B)} \\ AC=\sqrt{48}=4\sqrt3 \\ P=AC+AB+BC=12+4\sqrt3 \\ BC^2=AB^2+AC^2=\textgreater \Delta ABC~dr \\ R=\frac{abc}{4A}=\frac{4\cdot 8\cdot 4\sqrt3}{4\cdot\frac{4\cdot 4\sqrt3}{2}}=\frac{128\sqrt3}{32\sqrt3}=4[/tex]
