[student2009]

Пользуйся на здоровье.

Код:

function Otr(Ax, Ay, Bx, By: real): real;
begin
Result:=Abs(sqrt(sqr(Bx-Ax)+sqr(By-Ay)));
end;

function perim(Ax,Ay,Bx,By,Cx,Cy: real): real;
begin
Result:=Otr(Ax, Ay, Bx, By)+Otr(Bx, By, Cx, Cy)+Otr(Ax, Ay, Cx, Cy);
end;

function Area(Ax, Ay, Bx, By, Cx, Cy: real):real;
var p: real;
begin
p:=Perim(Ax, Ay, Bx, By, Cx, Cy)/2;
Result:=sqrt(p*(p-Otr(Ax, Ay, Bx, By))*
        (p-Otr(Bx, By, Cx, Cy))*(p-Otr(Cx, Cy, Ax, Ay)));
end;

procedure Dist(Px, Py, Ax, Ay, Bx, By: real; var D: real);
begin
D:=2*Area(Px, Py, Ax, Ay, Bx, By)/Otr(Ax, Ay, Bx, By);
end;