Encapsulating object creation

Suppose you have the following class hierarchy and a factory in your image viewer application.

interface Shape {
    // fields and methods
}

class Circle implements Shape {
    // fields and methods
}

class Polygon implements Shape {

    // fields and methods
}

class ShapeFactory {

    public Shape getShape(String type) {
        type = type.toUpperCase();

        switch (type) {
            case "CIRCLE":
                return new Circle();
            case "POLYGON":
                return new Polygon();
            default:
                return null;
        }
    }
}

Choose all working ways to get an instance of Polygon in this application.