(Display a pie chart) Write a program that uses a pie chart to display the percentages of the overall grade represented by projects, quizzes, midterm exams, and the final exam, as shown in Figure 14.46c

/*********************************************************************************
* (Display a pie chart) Write a program that uses a pie chart to display the     *
* percentages of the overall grade represented by projects, quizzes, midterm     *
* exams, and the final exam, as shown in Figure 14.46c. Suppose that projects    *
* take 20 percent and are displayed in red, quizzes take 10 percent and are      *
* displayed in blue, midterm exams take 30 percent and are displayed in green,   *
* and the final exam takes 40 percent and is displayed in orange. Use the Arc    *
* class to display the pies. Interested readers may explore the JavaFX PieChart  *
* class for further study.                                                       *
*********************************************************************************/
import javafx.application.Application;
import javafx.scene.Scene;
import javafx.stage.Stage;
import javafx.scene.shape.Arc;
import javafx.scene.shape.ArcType;
import javafx.scene.paint.Color;
import javafx.scene.layout.Pane;
import javafx.scene.text.Text;
import javafx.geometry.Insets;

public class Exercise_14_13 extends Application {
	@Override // Override the start method in the Application class
	public void start(Stage primaryStage) {

		// Create a pane
		Pane pane = new Pane();

		double[] scores = {20, 10, 30, 40};

		String[] grades = {"Project", "Quiz", "Midterm", "Final"};

		// Create four text objects
		Text t1 = new Text(110, 80,  grades[0] + " -- " + scores[0] + "%");
		Text t2 = new Text(80, 15,   grades[1] + " -- " + scores[1] + "%");
		Text t3 = new Text(5, 100,   grades[2] + " -- " + scores[2] + "%");
		Text t4 = new Text(100, 180, grades[3] + " -- " + scores[3] + "%");

		// Create four Arcs
		Arc arc1 = new Arc(100, 100, 80, 80, 0, 360 * (scores[0] / 100));
		arc1.setFill(Color.RED);
		arc1.setType(ArcType.ROUND);

		Arc arc2 = new Arc(100, 100, 80, 80, arc1.getStartAngle() + 
			arc1.getLength(), 360 * (scores[1] / 100));
		arc2.setFill(Color.BLUE);
		arc2.setType(ArcType.ROUND);

		Arc arc3 = new Arc(100, 100, 80, 80, arc2.getStartAngle() + 
			arc2.getLength(), 360 * (scores[2] / 100));
		arc3.setFill(Color.GREEN);
		arc3.setType(ArcType.ROUND);

		Arc arc4 = new Arc(100, 100, 80, 80, arc3.getStartAngle() + 
			arc3.getLength(), 360 * (scores[3] / 100));
		arc4.setFill(Color.ORANGE);
		arc4.setType(ArcType.ROUND);
		pane.getChildren().addAll(arc1, arc2, arc3, arc4, t1, t2, t3, t4);


		// Create a Scene and place it in the Stage;
		Scene scene = new Scene(pane);
		primaryStage.setTitle("Exercise_14_13"); // Set the stage title
		primaryStage.setScene(scene); // Place the scene in the stage
		primaryStage.show(); // Display the stage
	}
}