Задача в Делфи. Вероятно, не сложная.

unit Unit1;

interface

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

type
TForm1 = class(TForm)
dlina_t: TLabel;
dlina: TEdit;
obiem_t: TLabel;
plosh_t: TLabel;
plosh_p_t: TLabel;
Podchet: TButton;
Ochist: TButton;
Vixod: TButton;
obiem: TLabel;
plosh_b: TLabel;
plosh_p: TLabel;
procedure OchistClick(Sender: TObject);
procedure VixodClick(Sender: TObject);
procedure PodchetClick(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;

var
Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.OchistClick(Sender: TObject);
begin
dlina.Text:='';
obiem.Caption:='';
plosh_b.Caption:='';
plosh_p.Caption:='';
end;

procedure TForm1.VixodClick(Sender: TObject);
begin
Form1.Close;
exit;
end;

procedure TForm1.PodchetClick(Sender: TObject);
var
dlin:real;
ob:real;
plo_b:real;
plo_p:real;
begin
dlin:=StrToFloat(dlina.Text);
ob:=exp(3*ln(dlin));
plo_b:=4*sqr(dlin);
plo_p:=6*sqr(dlin);
obiem.Caption:=FloatToStrF(ob,ffGeneral,15,8);
plosh_b.Caption:=FloatToStrF(plo_b,ffGeneral,15,8);
plosh_p.Caption:=FloatToStrF(plo_p,ffGeneral,15,8);
end;

end.

Результат работы программы: