[kalinochkind]

У maskedit-ов ставишь editmask в 00

Код:

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, ExtCtrls, ComCtrls, StdCtrls, Mask, Buttons;

type
  TForm1 = class(TForm)
    medt1: TMaskEdit;
    btn1: TBitBtn;
    medt2: TMaskEdit;
    rg1: TRadioGroup;
    mmo1: TMemo;
    procedure btn1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

function srarifm:Real;
begin
Result:=(StrToInt(Form1.medt1.text)+strtoint(Form1.medt2.text))/2
end;

function srgeom:Real;
begin
Result:=Sqrt(StrToInt(Form1.medt1.text)*strtoint(Form1.medt2.text))
end;

procedure count;
begin
if Form1.rg1.ItemIndex=0 then Form1.mmo1.Lines.Append(FloatToStr(srarifm))
else Form1.mmo1.Lines.Append(FloatToStr(srgeom))
end;


procedure TForm1.btn1Click(Sender: TObject);
begin
count;
end;

end.