unit3.pas

一个小程序

unit Unit3;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

type
  TForm1 = class(TForm)
    Edit1: TEdit;
    Edit2: TEdit;
    Edit3: TEdit;
    Button1: TButton;
    Label1: TLabel;
    Label2: TLabel;
    Label3: TLabel;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
   const r=2.4;
   var x,y:real;
       b:boolean;
begin
   x:=strtofloat(edit1.Text);
   y:=strtofloat(edit2.Text);
   b:=(x*x+y*y)<=r*r;
   if b then edit3.text:='是'
        else edit3.text:='不是';
end;

end.