用java語言描述：
public class Circle { private double Radius;// 半徑
public Circle() {
}
public Circle(double radius) { Radius = radius;
}
// 求面積 public double getSize(double radius) {
return 3.14 * radius * radius;
}
// 求周長 public double getCircumference(double radius) {
return 2 * 3.14 * radius;
}
// 求體積 public double getVolume(double radius) {
return 4.0 / 3 * 3.14 * radius * radius * radius;
}
}