public class Square {

  // data member
  private double length;


  
  // Constructors
  //accepts r as length
  public Square (double l) {
    length = l;
  }
//no r? assume length is 1
  public Square() {
    length = 1;
  }
//copy's length from another circle
  public Square (Square s) {
    length = s.length;
  }

  // setter & getter
  // sets length
  public void setLength(double l) {
    length = l;
  }
//return length
  public double getLength() {
    return length;
  }

  // other methods
  public double area() {
    return Math.pow(length,2);
  }

  public double perimeter() {
    return length*4;
  }

}