Trying

src/main/java/fr/univamu/App.java

 package fr.univamu;
 
 
-import fr.univamu.svg.SvgElement;
-import myFiles.Circle;
-import myFiles.Shape;
-import myFiles.Vector2D;
-import myFiles.Regular;
+import static fr.univamu.svg.SvgAttribute.tag;
 
 import java.io.FileNotFoundException;
 
-import static fr.univamu.svg.SvgAttribute.tag;
+import fr.univamu.svg.SvgElement;
+import myFiles.Regular;
+import myFiles.Shape;
+import myFiles.Vector2D;
 
 public class App {
 
@@ -30,6 +29,6 @@ public class App {
   }
 
   public static void main(String[] args) throws FileNotFoundException {
-    write(new Regular(new Vector2D(1, 0), new Vector2D(0,1), new Vector2D(1, -1), new Vector2D(-1, 1)),"out/circle.svg");
+    write(new Regular(Vector2D.cartesian(1, 0), new Vector2D(0,0), new Vector2D(0, 1), new Vector2D(1, 1)),"out/circle.svg");
   }
 }