设三角形三边abc且a=b+1=c+2
a/sinA=c/sinC => ( c+2)/(2sinCcosC)=c/sinC => 2c cosC=c+2 .①
c²=a²+b²-2abcosC => c²=(c+2)²+(c+1)²-2(c+2)(c+1)cosC .②
① ②f方程组可解c值
则三角形的周长为3c+3
设三角形三边abc且a=b+1=c+2
a/sinA=c/sinC => ( c+2)/(2sinCcosC)=c/sinC => 2c cosC=c+2 .①
c²=a²+b²-2abcosC => c²=(c+2)²+(c+1)²-2(c+2)(c+1)cosC .②
① ②f方程组可解c值
则三角形的周长为3c+3