X^2-2V3x+2=0 ,公式法解得 a=V3+1,b=V3-1
2Sin(A+B)=2Sin(180-A-B)=2SinC
故2SinC = V3,SinC=V3/2,C=pi/3 或2/3 pi
CosC=1/2 或 -1/2
余弦定理c^2=a^2+b^2-2ab CosC
c^2=8+-2,c =V10或V6
面积S=1/2 ab * SinC=V3/2
X^2-2V3x+2=0 ,公式法解得 a=V3+1,b=V3-1
2Sin(A+B)=2Sin(180-A-B)=2SinC
故2SinC = V3,SinC=V3/2,C=pi/3 或2/3 pi
CosC=1/2 或 -1/2
余弦定理c^2=a^2+b^2-2ab CosC
c^2=8+-2,c =V10或V6
面积S=1/2 ab * SinC=V3/2