program egor;
uses crt;
var p,x1,y1,x2,y2,x3,y3,a,b,c,s:real;
BEGIN
writeln('koordinati x1, y1');
readln(x1,y1);
writeln('koordinati x2, y2');
readln(x2,y2);
writeln('koordinati x3, y3');
readln(x3,y3);
a:=sqrt(sqr(x1-x2)+sqr(y1-y2));
b:=sqrt(sqr(x2-x3)+sqr(y2-y3));
c:=sqrt(sqr(x3-x1)+sqr(y3-y1));
p:=(a+b+c)/2;
s:=sqrt(p*(p-a)*(p-b)*(p-c));
writeln('s=',s:3:2);
writeln('p=',p:3:2);
END.