function D(x1,x2,y1,y2:integer):real;
begin
d:=sqrt(sqr(x2-x1)+sqr(y2-y1));
end;
function PD(a,b,c:real):real;
begin
pd:=a+b+c;
end;
{-------------------------}
type TPoint=record
x,y:integer;
end;
function PP(a,b,c:TPoint):real;
begin
pp:=pd(d(a.x,b.x,a.y,b.y)+d(b.x,c.x,b.y,c.y)+d(a.x,c.x,a.y,c.y));
end;