👌 IMPROVE: create array of 3 figures and make Figure abstract

Signed-off-by: Jonas Sulzer <jonas@violoncello.ch>

src/Ex_01/FiguresGeometriques.java

 package Ex_01;
 
 public class FiguresGeometriques {
+    public static void main(String[] args) {
+        Figure[] figure = new Figure[3];
+        figure[0] = new RectangleColore(1.2, 3.4, 12.3, 43.2, 4);
+        figure[1] = new Cercle(2.3, 4.5, 12.2);
+        figure[2] = new Rectangle(1.3, 3.6, 2.3, 56.2);
+        for (int i = 0; i < figure.length; i++){
+            figure[i].affiche();
+            System.out.println("La surface de cette forme est :" + figure[i].surface());
+        }
+    }
 }
 
-class Figure {
+abstract class Figure {
     private double x;  // abscisse du centre
     private double y;  // ordonnée du centre
 
@@ -16,6 +26,8 @@ class Figure {
         System.out.println("centre = (" +  x + ", " + y + ")");
     }
 
+    public abstract double surface();
+
     public double getX() {
         return x;
     }