#include <stdio.h>
#include <math.h>
int main()
{
    double A,B,C,a,b,c,area,sinA,sinB;
    sinA=sin(A*3.14159/180);
    sinB=sin(B*3.14159/180);
    sin(A+B)=sin((A+B)*3.14159/180);
    scanf("%lf %lf %lf",&A,&B,&c);
    area=(c*c*sinA*sinB)/(2*sin(A+B));
    printf("area=%.3f",area);
    return 0;
}

#include <stdio.h>
#include <math.h>
int main()
{
 double A,B,C,a,b,c,area,sinA,sinB,sinAB;
 scanf("%lf %lf %lf",&A,&B,&c);
 sinA=sin(A*3.14159/180);
 sinB=sin(B*3.14159/180);
 sinAB=sin((A+B)*3.14159/180);
 
 area=(c*c*sinA*sinB)/(2*sinAB);
 printf("area=%.3f",area);
 return 0;
}

谢谢

上面做法运行结果也一样

上面运行结果一样