Mohon bantuannya. Menggunakan cara. Terima Kasih

Jawabannya E[tex] \frac{AC}{sin B} = \frac{AB}{sin C} \\ \\ \frac{15}{sin 30} =\frac{10}{sin C} \\ \\ 15 sin C = 10 . \frac{1}{2} \\ \\ sin C = \frac{5}{15}= \frac{1}{3} \\ \\ sin C= \frac{y}{r} = \frac{1}{3} \\ \\ x = \sqrt{ 3^{2}- 1^{2}} \\ \\ x= \sqrt{9-1} \\ \\ x= \sqrt{8} =2 \sqrt{2} \\ \\ cos C= \frac{x}{r} \\ \\ cos C=\frac{2 \sqrt{2 }}{3} \\ \\ cos C= \frac{2}{3} \sqrt{3} [/tex]