9.4 ������

� � � � � � � � � � � � � � � � � � � � � � � � � ��� � � � � � � ����

� � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � �H = 300 mm.; � H = 500 mm.; � H = 750 mm.