// Page 219

public class Circle implements Measurable
{
	private double myRadius;
	public Circle(double radius)
	{
		myRadius = radius;
	}
	public double getPerimeter()
	{
		return 2 * Math.PI * myRadius;
	}
	// Its own method, not belong the Measurable
	public double getCircumference()
	{
		return getPerimeter();
	}
	public double getArea()
	{
		return Math.PI * myRadius * myRadius;
	}
}