/* Note:Your choice is C IDE */
#include "stdio.h"
#include "stdlib.h"
#include "math.h"
void main()
{
 double  x1,y1,x2,y2,x3,y3,a,b,c,s,area;
  printf("请输入不在同一条直线上的3个坐标点:\n");
  scanf("%f,%f,%f,%f,%f,%f",&x1,&y1,&x2,&y2,&x3,&y3);
  a=sqrt((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2));
  b=sqrt((x1-x3)*(x1-x3)+(y1-y3)*(y1-y3));
  c=sqrt((x2-x3)*(x2-x3)+(y2-y3)*(y2-y3));
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