My work

src/App.java

 public class App {
     public static void main(String[] args) throws Exception {
-        Shape shape1 = new Triangle(3);
+        Shape shape1 = new Rectangle(3,4);
         shape1.draw();
+
     }
 }

src/Rectangle.java

+public class Rectangle extends Shape{
+  // Rectangle shape
+
+  private int width;
+  private int height;
+
+  public int getWidth() { 
+    return this.width; 
+  }
+
+  public int getHeight() { 
+    return this.height; 
+  }
+
+  public void setWidth(int width) { 
+    this.width = width; 
+  }
+
+  public void setHeight(int height) { 
+    this.height = height; 
+  }
+
+  public Rectangle() {
+    super();
+    this.setHeight(4);
+    this.setWidth(3);
+  }
+
+  public Rectangle(int width, int height) {
+    super();
+    this.setHeight(height);
+    this.setWidth(width);
+  }
+
+  
+
+  @Override  
+  public void draw() {
+
+    int width = this.getWidth();
+    int height = this.getHeight();
+
+    // Top
+    System.out.print(" "+new String(new char[width]).replace("\0", "-")+"\n");
+
+    // Rows
+    for (int loop1=0; loop1<height; loop1++){
+      System.out.print("|"+new String(new char[width]).replace("\0", " ")+"|"+"\n");
+    }
+    
+    System.out.print(" "+new String(new char[width]).replace("\0", "-")+"\n");
+  }
+
+  @Override
+  public float area() {
+
+    float area = this.getWidth() * this.getHeight();
+    return area;
+  }
+
+  @Override
+  public float circumference() {
+    float circ = 2*this.getWidth()+2*this.getHeight();
+    return circ;
+  }
+
+}

src/Shape.java

@@ -17,4 +17,6 @@ abstract public class Shape {
     this.size = size;
   }
 
+  
+
 }

src/Square.java

+public class Square extends Shape{
+  // An equilateral triangle
+
+  public Square() {
+    super();
+  }
+  public Square(int i) {
+    super(i);
+  }
+
+  @Override  
+  public void draw() {
+
+    int size = this.getSize();
+    // Top
+    System.out.print(new String(new char[size]).replace("\0", "-")+"\n");
+
+    // Rows
+
+    for (int loop1=0; loop1<size; loop1++){
+      System.out.print("|"+new String(new char[size-2]).replace("\0", " ")+"|"+"\n");
+    }
+    
+    System.out.print(new String(new char[size]).replace("\0", "-")+"\n");
+  }
+
+  @Override
+  public float area() {
+
+    float area = this.getSize() * this.getSize();
+    return area;
+  }
+
+  @Override
+  public float circumference() {
+    float circ = this.getSize()*4;
+    return circ;
+  }
+
+}