import java.util.Scanner;

public class CirclePlay
{
    public static void printGreeting()
    {
        System.out.println("Welcome to the Circle Calculator");
        System.out.println();
        System.out.println("This application will calculate the area of a circle and/or volume of a sphere.");
        System.out.println();
    }

    public static double enterRadius()
    {
        Scanner keyboard;
        double radius;

        keyboard = new Scanner(System.in);

        System.out.print("Enter the radius: ");
        radius = keyboard.nextDouble();

        return radius;
    }

    public static double calculateArea(double radius)
    {
        return Math.PI * radius * radius;
    }

    public static double calculateVolume(double radius)
    {
        return Math.PI * 4 / 3 * Math.pow(radius, 3);
    }

    public static String format2(double number)
    {
        return String.format("%.2f", number);
    }
}