由题知：a+b+c=√2+1由正弦定理知：a/sinA=b/sinB=c/sinC令:a/sinA=b/sinB=c/sinC=K所以：a=KsinAb=KsinBc=KsinC所以：K(sinA+sinB+sinC)=√2+1,sinA+sinB+sinC=（√2+1）/K (1)sinA+sinB=√2sinC (2)(1)-(2)sinC+√...