输入三角形的三边长，输出三角形的面积
热心网友
首先摆几个公式.S=1/2*a*b*sin(A);cos(A)=(b*b+a*a-c*c)/2/a/b;cos(A)*cos(A)+sin(A)*sin(A)=1;#include #include int main(){float a,b,c;float cosA,sinA,S;while(scanf("%f%f%f",&a,&b,&c)){if(a=b+c || b=a+c || c=a+b)printf("数据有问题\n");else{cosA=(float)(b*b+a*a-c*c)/2/a/b;sinA=sqrt(1-cosA*cosA);S=0.5*a*b*sinA;printf("%f\n",S);}}}
热心网友
#include#includeint main(){float a,b,c,p;scanf("%f %f %f",&a,&b,&c);p=(a+b+c)/2.0;printf("%f",sqrt(p*(p-a)*(p-b)*(p-c)));return(0);}