5个WA??????????????????????????????????????????????

#include <bits/stdc++.h>
using namespace std;

int main(){
	  double x1,y1,x2,y2,x3,y3,a,b,c;
      cin>>x1>>y1>>x2>>y2>>x3>>y3;
      a=sqrt(pow(x2-x1,2)*pow(y2-y1,2));
      b=sqrt(pow(x3-x2,2)*pow(y3-y2,2));
      c=sqrt(pow(x1-x3,2)*pow(y1-y3,2));
      cout<<fixed<<setprecision(2);      
      cout<<a+b+c;
} 

嘤嘤嘤(;´༎ຶД༎ຶ`)