public Circle(IShapeVisualizer visualizer, int radius) : base(visualizer) { Radius = radius; }
public Square(IShapeVisualizer visualizer, int side) : base(visualizer, side, side) { }
public Rectangle(IShapeVisualizer visualizer, int width, int height) : base(visualizer) { Width = width; Height = height; }
public Shape(IShapeVisualizer visualizer) { _visualizer = visualizer; }