[N=D],[" 38.A shuttlecock used for "],[" playing badminton has "],[" the shape of a frustum "],[" of a cone mounted on a "],[" hemisphere as shown in "],[" the figure.The extemal "],[" diameters of the frustum "],[" diameters of the frustum "],[" diameters of the frustum "],[" are "6cm" and "2cm" and "],[" the height of the entire shuttlecock is "7cin" ."],[" Find its external surface area."],[" Or "]