segitiga ABC mempunyai panjang sisi a,b,c. jika a + b = 10, sudut A = 30° dan sudut B = 60°, panjang sisi B =

a+b = 10
a = 10 - b
[tex] \frac{10 - b}{ \sin(30) } = \frac{b}{ \sin(60) } \\ (10 - b). \sin(60) = b. \sin(30) \\ (10 - b). \frac{ \sqrt{3} }{2} = b. \frac{1}{2} \\ 10 \sqrt{3} - b \sqrt{3} = b \\ b + b \sqrt{3} = 10 \sqrt{3} \\ b(1 + \sqrt{3} ) = 10 \sqrt{3} \\ b = \frac{10 \sqrt{3} }{1 + \sqrt{3} } = \frac{10 \sqrt{3} (1- \sqrt{3}) }{ - 2} = - 5 \sqrt{3} + 15[/tex]