2B=A+C3B=A+B+C=180°B=60°方程 x²-3x+2=√3(x-1)(x-1)(x-2)=√3(x-1)x=1或x=2+√3tanC=2+√3,tanA=1C=75°,A=45°a/sinA=b/sinB=c/sinCb=asinB/sinAc=asinC/sinAS=(bcsinA)/2=a²sinBsinC/(2sinA)3-√3=a...额。为什么我这里a的答案是2。。抱歉，我的答案有误从这儿开始改吧S=(bcsinA)/2 =a²sinBsinC/(2sinA)3-√3=a²*(√3/2)*(√2/2)/[(√6+√2)/2]3-√3=a²*(√3*√2)/[2(√6+√2)]√6a²=2（3-√3）(√6+√2)=2√3(√3-1)*√2(√3+1)a²=2(√3-1)(√3+1)a²=4a=2