public class RegularPolygon extends Polygon implements Form, Transformable { protected double side; private int nbSides; public RegularPolygon(int nbSides, double side) { this.side = side; this.nbSides = nbSides; } public int getnumberOfSides() { return nbSides; } public double[] getSides() { double[] sides= new double[nbSides]; for(int i = 0 ; i < nbSides ; i++) sides[i]=side; return sides; } public double perimeter () { return side*nbSides; } public double area () { return nbSides * side * side / Math.tan(Math.PI/nbSides)/4; } public void enlarge(double factor) { if (factor > 0) side *= factor; else System.err.println( this + "impossible to zoom with a non positive factor !"); } public String toString() { return "Polygone(" + nbSides + " * " + side + ")" ; } }