interface Shape { double area(); double girth(); } class Rectangle implements Shape { int a,b; public Rectangle(int aa, int bb) { a=aa; b=bb; } public double area() { return a*b; } public double girth() { return 2*(a+b); } } public class XXK3 { public static void main(String[] args) { Shape x; x=new Rectangle(6,10); System.out.println(x.area()+", "+x.girth()); } } 程序运行的结果是 ( )。