Area Calculator - How To Move All Input / Output To Main

I am stuck on one of the projects: Area Calculator

I am able to code an area calc that works, but am unsure how to move all the input/output to main like the project wants. here is a piece of my code so far:

public static void main( String[] args )
{
Scanner kb = new Scanner(System.in);
int base = 0, height = 0, width = 0, radius = 0, choice;
System.out.println( "-=-=-=-=-=-=-=-=-=-=-" );
System.out.println( "1. Triangle" );
System.out.println( "2. Rectangle" );
System.out.println( "3. Square" );
System.out.println( "4. Circle" );
System.out.print( "Pick a shape: " );

[Code] ....

I have the same thing for rectangle, square, and circle (of course with the correct formulas) and the program works perfect, but the assignment is still wrong until I can move the input/output to main. what do I do?