大神在哪里

#include<stdio.h>
#include<stdlib.h>
#include<math.h>
using namespace std;
int dis(float ax,float ay,float bx,float by,float d);
int main()
{ float x1,x2,x3,y1,y2,y3,d1,d2,d3,s,p;
scanf("%f %f %f %f %f %f",&x1,&y1,&x2,&y2,&x3,&y3);
d1=dis(x1,y1,x2,y2);
d2=dis(x2,y2,x3,y3);
d3=dis(x1,y1,x3,y3);
p=(dis1+dis2+dis3)/2
s=sqrt(p*(p-dis1)*(p-dis2)*(p-dis3));
printf("%.2f",s);
system(pause);
return 0;
}
int dis(float ax,float ay,float bx,float by,float d)
{ dis=sqrt(pow(ax-bx,2)+pow(ay-by,2));
return d;
}
[Error] too few arguments to function 'int dis(float, float, float, float, float)'