tolong dibantu ya kak.. pake caranya juga..

6. pakai aturan cosinus bc =x

[tex] {x}^{2} = {(6 \sqrt{3} )}^{2} + {4}^{2} - 2 \times 6 \sqrt{3} \times 4 \times \cos(30) \\ {x}^{2} = 108 + 16 - 36 \\ x = \sqrt{88} \\ x = 2 \sqrt{22} [/tex]