题目：abstract class Shape { int a,b; public Shape(int aa, int bb) {a=aa; b=bb;} abstract public double area(); } class Rectangle extends Shape { public Rectangle(int aa, int bb) {super(aa,bb);} public double area() {return a*b;} } class Triangle extends Shape { public Triangle(int aa, int bb) {super(aa,bb);} public double area() {return a*b/2;} } public class XXK3 { public static void main(String[] args) { Shape x,y; x=new Rectangle(10,20); y=new Triangle(10,15); System.out.println(x.area()+", "+y.area()); } }
A:200.1, 75.1
B:200.0, 75.0
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