3)var x1,y1,x2,y2,x3,y3,p,s,a,b,c:real;
begin;
readln(x1);
readln(y1);
readln(x2);
readln(y2);
readln(x3);
readln(y3);
s:=0.5*((x1-x3)*(y2-y3)-(x2-x3)*(y1-y3));
a:=sqrt(sqr(x2-x1)+sqr(y2-y1));
b:=sqrt(sqr(x3-x2)+sqr(y3-y2));
c:=sqrt(sqr(x3-x1)+sqr(y3-y1));
p:=a+b+c;
writeln('Площадь:',s);
write('Периметр:',p);
end.