public class Ellipse extends GeometricObject {
  //inherits from superclass GeometricObject: 
  //  methods: getColor setColor isFilled setFilled getDateCreated toString
  //  Can not directly access inherited 'color' 'filled' 'dateCreated' fields
  //  because they are private in superclass.
  private double a, b;

  public Ellipse() {
    //compiler inserts: super();  //call of superclass' 0-arg constructor
  }

  public Ellipse(double a, double b) {
    //compiler inserts: super();
    this.a = a;
    this.b = b;
  }

  public double getArea() {
    return a * b * Math.PI;
  }
  
  public double getPerimeter() {
    return Math.PI*(3*(a+b)-Math.sqrt((3*a+b)*(a+3*b)));
  }
  
  public String toString() {
    return super.toString() + "  a: " + a + "  b: " + b;
  }
}