@@ -0,0 +1,251 @@
+public class Circle extends Shape2D %7B //%0A    private double radius; //b%7C%0A    private static final double PI = 3.141592654; %0A    public Circle(double r) %7B%0A        radius = r;%0A    %7D%0A    public double area() %7B%0A        return PI * radius * radius;%0A    %7D%0A%7D

fix bug