[tex]\displaystyle\\
\text{Se da:}\\
\Delta ABC\\
AB=4\text{ cm}\\
BC = 8\text{ cm}\\
Aria = 8\text{ cm}^2\\
\text{Se cere:}\\
m(\sphericalangle B)= ?\\\\
\text{Rezolvare:}\\\\
Aria = \frac{AB\cdot BC \cdot \sin(B)}{2}=8\\\\
AB\cdot BC \cdot \sin(B)=2\cdot8\\\\
AB\cdot BC \cdot \sin(B)=16\\\\
\sin(B) = \frac{16}{AB\cdot BC} = \frac{16}{4\cdot 8}= \frac{16}{32}=\boxed{\bf \frac{1}{2}}\\\\
\Longrightarrow~~\boxed{\bf m(\sphericalangle B)=30^o}
[/tex]
