program dientich;

uses crt;

var r1,r2,r3:real;

{---CT-con---}

function dt(r:real):real;

begin

     dt:=r*r*3.14;

end;

{---CT-chinh---}

BEGIN
     clrscr;

     write('Nhap ban kinh hinh tron thu nhat: ');  readln(r1);

     write('Nhap ban kinh hinh tron thu hai: ');  readln(r2);

     write('Nhap ban kinh hinh tron thu ba: ');  readln(r3);

     writeln('Dien tich hinh tron thu nhat la: ',dt(r1));

     writeln('Dien tich hinh tron thu hai la: ',dt(r2));

     writeln('Dien tich hinh tron thu ba la: ',dt(r3));

     readln;

end.

program phuongt;
uses crt;
  var r1, r2, r3: real;
function dientich(r: real): real;
begin
        dientich:=r*r*3.14;
end;
function chuvi(r: real): real;
begin
         chuvi:=2*r*3.14;
end;
begin
        clrscr;
        write('Nhap ban kinh hinh tron 1: '); readln(r1);
        write('Nhap ban kinh hinh tron 2: '); readln(r2);
        write('Nhap ban kinh hinh tron 3: '); readln(r3);
        writeln('Chu vi hinh tron 1: ', chuvi(r1):2:1);
        writeln('Chu vi hinh tron 2: ', chuvi(r2):2:1);
        writeln('Chu vi hinh tron 3: ', chuvi(r3):2:1);
        writeln('Dien tich hinh tron 1: ', dientich(r1):2:1);
        writeln('Dien tich hinh tron 2: ', dientich(r2):2:1);
        writeln('Dien tich hinh tron 3: ', dientich(r3):2:1);
        readln
end.