这是我编的
/*给10z组a b c求证若组成三角形求其周长 面积（精确小数点两位） 不成立输出a b c*/
#include<stdio.h>
#include<math.h>
int main(void)
{
    int i;
    double a,s,b,c,m,area;    /*m为周长，area为面积*/
    for(i=1;i<=10;i++){
        printf("enter a b c:");
        scanf("a=%lf,b=%lf,c=%lf\n",a,b,c);
        if(a+b>c&&a-b<c){
            m=a+b+c;
            s=(a+b+c)/2;
            area=sqrt(s*(s-a)*(s-b)*(s-c));
            printf("m=%.2f,area=%.2f\n",m,area);
        }
        else{
            printf("a=%.2f,b=%.2f,c=%.2f\n",a,b,c);
        }
    }
    return 0;
}
输出结果是乱码 好多数字
                enter a b c:4 5 6
a=-92559631349317831000000000000000000000000000000000000000000000.00,b=-92559631
349317831000000000000000000000000000000000000000000000.00,c=-9255963134931783100
0000000000000000000000000000000000000000000.00
enter a b c:a=-92559631349317831000000000000000000000000000000000000000000000.00
,b=-92559631349317831000000000000000000000000000000000000000000000.00,c=-9255963
1349317831000000000000000000000000000000000000000000000.00
enter a b c:a=-92559631349317831000000000000000000000000000000000000000000000.00
,b=-92559631349317831000000000000000000000000000000000000000000000.00,c=-9255963
1349317831000000000000000000000000000000000000000000000.00
enter a b c:a=-92559631349317831000000000000000000000000000000000000000000000.00
,b=-92559631349317831000000000000000000000000000000000000000000000.00,c=-9255963
1349317831000000000000000000000000000000000000000000000.00
enter a b c:a=-92559631349317831000000000000000000000000000000000000000000000.00
,b=-92559631349317831000000000000000000000000000000000000000000000.00,c=-9255963
1349317831000000000000000000000000000000000000000000000.00
enter a b c:a=-92559631349317831000000000000000000000000000000000000000000000.00
,b=-92559631349317831000000000000000000000000000000000000000000000.00,c=-9255963
1349317831000000000000000000000000000000000000000000000.00
enter a b c:a=-92559631349317831000000000000000000000000000000000000000000000.00
,b=-92559631349317831000000000000000000000000000000000000000000000.00,c=-9255963
1349317831000000000000000000000000000000000000000000000.00
enter a b c:a=-92559631349317831000000000000000000000000000000000000000000000.00
,b=-92559631349317831000000000000000000000000000000000000000000000.00,c=-9255963
1349317831000000000000000000000000000000000000000000000.00
enter a b c:a=-92559631349317831000000000000000000000000000000000000000000000.00
,b=-92559631349317831000000000000000000000000000000000000000000000.00,c=-9255963
1349317831000000000000000000000000000000000000000000000.00
enter a b c:a=-92559631349317831000000000000000000000000000000000000000000000.00
,b=-92559631349317831000000000000000000000000000000000000000000000.00,c=-9255963
1349317831000000000000000000000000000000000000000000000.00
Press any key to continue

这个问题我改过了  不过输出的还是乱码

我还分开搞/*给10z组a b c求证若组成三角形求其周长 面积 b不成立输出a b c*/
#include<stdio.h>
#include<math.h>
int main(void)
{
    int i;
    double a,s,b,c,m,area;    /*m为周长，area为面积*/
    for(i=1;i<=10;i++){
        printf("enter a:");
        scanf("\n",&a);
        printf("enter b:");
        scanf("\n",&b);
        printf("enter c:");
        scanf("\n",&c);
        if(a+b>c&&a+c>b&&b+c>a){
            m=a+b+c;
            s=(a+b+c)/2;
            area=sqrt(s*(s-a)*(s-b)*(s-c));
            printf("m=%f,area=%f\n",m,area);
        }
        else{
            printf("a=%f,b=%f,c=%f\n",a,b,c);
        }
    }
    return 0;
}