Question

Daca in triunghiul abc ab=4 ac=5 si aria triunghiului este de 5 cm patrati. M <(BAC)?

Answer 1

[tex]A_{ABC}=\frac{AB\cdot AC\sin A}{2} \Rightarrow \frac{5\cdot4\sin A}{2}=5\Rightarrow\\\ 20\cdot\sin A=10\Rightarrow \sin A=\frac{1}{2}\Rightarrow m(\measuredangle BAC)=30^0 \text{ sau }m(\measuredangle BAC)=120^0\\ [/tex]