Kuebjii's Calculator V1

import java.util.ArrayList;
import java.util.Scanner;
import java.util.Random;
import java.util.concurrent.TimeUnit;
import java.awt.Graphics;

class ANSIConstants {
    public static final String ANSI_RESET = "\u001B[0m";
    public static final String ANSI_BLACK = "\u001B[30m";
    public static final String ANSI_RED = "\u001B[31m";
    public static final String ANSI_GREEN = "\u001B[32m";
    public static final String ANSI_YELLOW = "\u001B[33m";
    public static final String ANSI_BLUE = "\u001B[34m";
    public static final String ANSI_PURPLE = "\u001B[35m";
    public static final String ANSI_CYAN = "\u001B[36m";
    public static final String ANSI_WHITE = "\u001B[37m";
}
public class Main {

    public static void circles ()
    {
        System.out.println("What is the radius of the circle?");
        Scanner reader = new Scanner (System.in);
        double radius = reader.nextDouble();
        double circumference;
        double area;
        circumference = 2 * 3.14 * radius;
        area = 3.14 * radius * radius;
        System.out.println("Here is the circumference of the circle" + circumference);
        System.out.println("Here is the area of the circle" + area);
        System.out.println();
        System.out.println("Continue back to the menu?");
        String nothing = reader.nextLine();
        if (nothing == ""){
            KuebjiiCalculatorMenu();
        }
        KuebjiiCalculatorMenu();

    }

    public static void squares ()
    {
        Scanner reader = new Scanner(System.in);
        System.out.println("Please enter one side of the square");
        double side = reader.nextDouble();
        double perimeter;
        double area;

        perimeter = side + side + side + side;
        area = side * side;

        System.out.println("Here is the perimeter of the square: " + perimeter);
        System.out.println("Here is the area of the square: " + area);
        System.out.println();
        System.out.println("Continue back to the menu?");
        String nothing = reader.nextLine();
        if (nothing == ""){
            KuebjiiCalculatorMenu();
        }
        KuebjiiCalculatorMenu();
    }
    public static void rectangle ()
    {
        Scanner reader = new Scanner (System.in);
        System.out.println("Please enter the length of the rectangle");
        double length = reader.nextDouble();
        System.out.println("Please enter the width of the rectangle");
        double width = reader.nextDouble();

        double perimeter = 2 * (length * width);
        double area = length * width;

        System.out.println("Here is the perimeter of the rectangle: " + perimeter);
        System.out.println("Here is the area of the rectangle: " + area);
        System.out.println();
        System.out.println("Continue back to the menu?");
        String nothing = reader.nextLine();
        if (nothing == ""){
            KuebjiiCalculatorMenu();
        }
        else
        {
            KuebjiiCalculatorMenu();
        }
    }

    public static void KuebjiiCalculatorMenu()
    {
        Scanner reader = new Scanner(System.in);
        System.out.println("Welcome to Kuebjii's Calculator");
        System.out.println("1. Circle");
        System.out.println("2. Square");
        System.out.println("3. Rectangle");
        System.out.println("Please type out the number you would like to use");
        int selector = reader.nextInt();
        if (selector == 1){
            circles();
        }
        if (selector == 2){
            squares();
        }
        if (selector == 3)
        {
            rectangle();
        }
        if (selector == 4)
        {
            devMode();
        }
    }

    public static void main(String[] args) throws InterruptedException {
        System.out.println(ANSIConstants.ANSI_RED + "Checking for first construction" + ANSIConstants.ANSI_RESET);
        Thread.sleep(1000);
        System.out.println(ANSIConstants.ANSI_GREEN + "DONE" + ANSIConstants.ANSI_RESET);
        System.out.println(ANSIConstants.ANSI_RED + "Checking for Second construction" + ANSIConstants.ANSI_RESET);
        Thread.sleep(4000);
        System.out.println(ANSIConstants.ANSI_GREEN + "DONE" + ANSIConstants.ANSI_RESET);
        Thread.sleep(5000);
        System.out.print(ANSIConstants.ANSI_CYAN + "Loading." + ANSIConstants.ANSI_RESET);
        System.out.print(ANSIConstants.ANSI_CYAN + "." + ANSIConstants.ANSI_RESET);Thread.sleep(1000);System.out.print(ANSIConstants.ANSI_CYAN + "." + ANSIConstants.ANSI_RESET);Thread.sleep(1000);System.out.print(ANSIConstants.ANSI_CYAN + "." + ANSIConstants.ANSI_RESET);Thread.sleep(1000);System.out.print(ANSIConstants.ANSI_CYAN + "." + ANSIConstants.ANSI_RESET);Thread.sleep(1000);
        Thread.sleep(1000);System.out.print(ANSIConstants.ANSI_CYAN + "." + ANSIConstants.ANSI_RESET);Thread.sleep(1000);System.out.print(ANSIConstants.ANSI_CYAN + "." + ANSIConstants.ANSI_RESET);Thread.sleep(1000);System.out.print(ANSIConstants.ANSI_CYAN + "." + ANSIConstants.ANSI_RESET);
        System.out.println();
        System.out.println();
        KuebjiiCalculatorMenu();
    }
    public static void devMode ()
    {
        Scanner reader = new Scanner(System.in);
        System.out.println("D E V   C O N S O L E");
        System.out.println("1. Circle");
        System.out.println("2. Square");
        System.out.println("3. Rectangle");
        System.out.println("4. Testing Cycle");
        int selector = reader.nextInt();
        if (selector == 1){
            System.out.println("What is the radius of the circle?");
            double radius = reader.nextDouble();
            double circumference;
            double area;
            circumference = 2 * 3.14 * radius;
            area = 3.14 * radius * radius;
            System.out.println("Radius = " + radius + " Equation for circumference: 2 * 3.14 * " + radius);
            System.out.println("Radius = " + radius + " Equation for area: 3.14 * " + radius + " * " + radius);
            System.out.println("Here is the circumference of the circle: " + circumference);
            System.out.println("Here is the area of the circle: " + area);
        }
        if (selector == 4)
        {
            System.out.println(ANSIConstants.ANSI_CYAN + "testing the cyan color" + ANSIConstants.ANSI_RESET);
        }

        }
    }