package example;
//* A point in the plane
public abstract class Point {
	//* Abscissa
	public abstract double x();
	//* Ordinate
	public abstract double y();
	//* Radius
	public abstract double r();
	//* Azimuth
	public abstract double theta();
	//* Distance from an other point p
	public double distanceFrom(Point p) {
		return Math.hypot(this.x() - p.x(), this.y() - p.y());
	}
}