Sudut a =60 sudut b=45 bc=12cm rusuk ac??

[tex] \frac{ac}{sinb} = \frac{bc}{sin \: a} \\ \frac{ac}{sin45} = \frac{12}{sin60} \\ \frac{ac}{ \frac{1}{2} \sqrt{2} } = \frac{12}{ \frac{1}{2} \sqrt{3} } \\ ac \times \frac{1}{2} \sqrt{3} = 12 \times \frac{1}{2} \sqrt{2} \\ ac = 6 \sqrt{2} \times \frac{2}{ \sqrt{3} } \\ ac = \frac{12}{3} \sqrt{2} \sqrt{3} \\ ac = 4 \sqrt{6} [/tex]