Circle.java

public class Circle{
  //Field
  private int radius;

  //Specified (parameterized) Constructor
  public Circle( int r ){
    radius = r;
  }

  //Accessor
  public int getRadius(){
    return radius;
  }

  //Mutator
  public void setRadius( int r ){
    radius = r;
  }

  //area - calculates and returns the area of the circle
  public double area(){
    return Math.PI * Math.pow( radius, 2 );
  }

  //circumference - calculates and returns the circumference of the circle
  public double circumference(){
    return 2 * Math.PI * radius;
  }

  //toString - returns a textually representative String of the Circle object
  public String toString(){
    return "This circle has a radius of " + radius;
  }

  //equals - returns true if two circle have the exact same radius
  public boolean equals( Circle other ){
    return this.getRadius() == other.getRadius();
  }
}