[tex]BC=a \sqrt{3} \\ sinB= \frac{ \sqrt{6} }{3} = \frac{AC}{BC} \\ AC=BC*sinB= \frac{a \sqrt{18} }{3} = \frac{3a \sqrt{2} }{3}=a \sqrt{2} \\ AB= \sqrt{BC^2-AC^2}= \sqrt{(a \sqrt{3})^2-(a \sqrt{2})^2 }= \sqrt{3a^2-2a^2}= \sqrt{a^2}=a \\ sin C= \frac{AB}{BC}= \frac{a}{a \sqrt{3} }= \frac{1}{\sqrt{3}} = \frac{\sqrt{3}}{3} [/tex]