第七周能否构成三角形



<img src="http://img.blog.csdn.net/20161013202617414?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQv/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center" alt="" />#include <stdio.h>#include <math.h>int main(){    float a,b,c,s,area;    scanf("%f%f%f",&a,&b,&c);    if (a+b>c&&c+a>b&&b+c>a)    {        s=(a+b+c)/2;        area=sqrt(s*(s-a)*(s-b)*(s-c));        printf("area=%.2f",area);    }    else    {        printf("error input");    }    return 0;}

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