Circle.radiusProperty() has the following syntax.
public final DoubleProperty radiusProperty()
In the following code shows how to use Circle.radiusProperty() method.
//from ww w . j a va 2 s . c o m import javafx.application.Application; import javafx.scene.Group; import javafx.scene.Scene; import javafx.scene.paint.Color; import javafx.scene.shape.Circle; import javafx.stage.Stage; public class Main extends Application { public static void main(String[] args) { Application.launch(args); } @Override public void start(Stage primaryStage) { primaryStage.setTitle("Title"); final Circle circ = new Circle(40,Color.RED); System.out.println(circ.radiusProperty().doubleValue()); final Group root = new Group(circ); final Scene scene = new Scene(root, 400, 300); primaryStage.setScene(scene); primaryStage.show(); } }