// Unverändert. public class Kreis extends Grundflaeche { private int radius; public Kreis(int radius) { this.radius = radius; } public int getRadius() { return radius; } @Override public double umfang() { return 2 * Math.PI * radius; } @Override public double flaeche() { return Math.PI * Math.pow(radius, 2); } @Override public String toString() { return "Kreis{radius=" + radius + "; " + super.toString() + "}"; } }