6.
[tex]\it T. \ \ sinusurilor:\\ \\ \dfrac{AC}{sinB}=\dfrac{BC}{sinA} \Rightarrow sinB=\dfrac{AC\cdot sinA}{BC}=\dfrac{2\cdot sin30^o}{4}=\dfrac{2\cdot\dfrac{1}{2}}{4}=\dfrac{1}{4}[/tex]
7.
[tex]\it T.\ P.\ \Rightarrow AC=5\ cm\\ \\ sinB=\dfrac{AC}{BC}=\dfrac{5}{13}[/tex]
