So, after two days of trying to figure out the problem, I've decided to come to the experts for advice. Here is my code:

import java.util.Scanner; public class Quiz7 { public static void main(String[] args) { String radius; Scanner keyboard = new Scanner(System.in); String programName; String dueDate; System.out.print("What is the name of the program? "); programName=keyboard.nextLine(); System.out.print("What is the due date of the program? "); dueDate=keyboard.nextLine(); int iMenuInput = 0; final double PI = 3.1416f; displayMyInfo(programName, dueDate); menu(); AreaCircle(); }//end of main public static void displayMyInfo(String programName, String dueDate) { System.out.print("The program name is" +programName); System.out.print("The due date of the program is" +dueDate); }//end of displayMyInfo public static int menu() { Scanner kb2 = new Scanner(System.in); int iMenuInput; System.out.print("* * * * * * * * M E N U * * * * * * * *"); System.out.print("\n\n1> Area of a circle"); System.out.print("\n2> Circumference of a circle"); System.out.print("\n3> Area of a rectangle"); System.out.print("\n4> Perimeter of a rectangle"); System.out.print("\n5> Volume of a box"); System.out.print("\n6> Volume of a cone"); System.out.print("Enter your choice "); iMenuInput=kb2.nextInt(); System.out.print (" OR 2, OR 3, OR 4, ETC"); return iMenuInput; }//end of menu public static double AreaCircle(int radius) { final double PI = 3.1416f; double dAreaCircle; dAreaCircle = PI * radius * radius; return dAreaCircle; }//end of areaCircle public static double circumference(int radius) { final double PI = 3.1416f; float fCircumference; fCircumference = (float)(2 * PI * radius); return fCircumference; }//end of circumference public static int areaRectangle(int length, int width) { int iAreaRectangle; iAreaRectangle = length * width; return iAreaRectangle; }//end of areaRectangle public static int perimeterRectangle(int length, int width) { int iPerimeterRectangle; iPerimeterRectangle = 2 *(length * width); return iPerimeterRectangle; }//end of perimeterRectangle public static int volumeBox(int length, int width, int height) { int iVolumeBox; iVolumeBox = length * width * height; return iVolumeBox; }//end of volumeBox public static double volumeCone(int radius, int height) { final double PI = 3.1416f; float fVolumeCone; fVolumeCone = (float)(PI*radius*radius*radius*height)/3.0f; return fVolumeCone; }//end of volumeCone }//end of Quiz7

The problem seems to lie on line 19, with the error: AreaCircle(int) in Quiz7 cannot be applied to ()

AreaCircle();

Thanks for your help in advance!