三角形的面积 = 1/2 ab sinC = 1/2ab 根号3 / 2 = 根号3
ab = 4
cos C = (a^2+b^2-c^2) / (2ab) = 1/2
a^2+b^2 = 8
a = 2,b = 2
sin B = 2 sin A
a / sinA = b / sin B
a = b/2
cos C = (a^2+b^2-c^2) / (2ab) = 1/2
a= 2根号3 / 3
b = 4根号3 / 3
三角形ABC的面积 = 1/2 ab sinC = 2根号3 / 3