Using super keyword

[Roger Fed]

hello,
I've developed these two classes, they are related by inheritance
when the last line executed in main , i want the "toString()" in the subclass call the "toString()" in the super class
I've tried to put this line "super.toString()" inside the the method in the subclass but it give me syntax error
I'd be grateful if you help me
thanks in advance.
this is main

 public static void main(String[] args) {
        Triangle t1=new Triangle(1, 1.5, 1);
        t1.setColor("Yello");
        t1.setFilled(true);
        System.out.println(t1.toString());
    }

public class  Triangle extends GeometricObject {
    private double side1=1.0;
    private double side2=1.0;
    private double side3=1.0;
    ////////////////////////
    public Triangle(){
    }
    public Triangle(double side1,double side2,double side3){
        this.side1=side1;
        this.side2=side2;
        this.side3=side3;
    }
    public double getSide1(){
        return side1;
    }
    public double getSide2(){
        return side2;
    }
    public double getSide3(){
        return side3;
    }
    public double getPerimeter(){
        return (side1+side2+side3);
    }
    public double getArea(){
        double s=(side1+side2+side3)/2;
        return (Math.sqrt(s*(s - side1)*(s - side2)*(s - side3)));
    }
    public String toString(){
        return "Triangle: side1 = " + side1 + " side2 = " + side2 +
  " side3 = " + side3;

    }

and this is the GeometricObject class

public class GeometricObject {
  private String color = "white";
  private boolean filled;
  private java.util.Date dateCreated;

  /** Construct a default geometric object */
  public GeometricObject() {
    dateCreated = new java.util.Date();
  }

  /** Return color */
  public String getColor() {
    return color;
  }

  /** Set a new color */
  public void setColor(String color) {
    this.color = color;
  }

  /** Return filled. Since filled is boolean,
     so, the get method name is isFilled */
  public boolean isFilled() {
    return filled;
  }

  /** Set a new filled */
  public void setFilled(boolean filled) {
    this.filled = filled;
  }

  /** Get dateCreated */
  public java.util.Date getDateCreated() {
    return dateCreated;
  }

  /** Return a string representation of this object */
  public String toString() {
    return "created on " + dateCreated + "\ncolor: " + color +
      " and filled: " + filled;
  }

[Christophe Verré]

There shouldn't be any problem. Can you show exactly how and where you wrote it ?