java 1st program crits
<p>Just started learning Java, wrote a basic program that calculates the area of user selected shapes.  Can I get crits and comments on things I've done right and wrong. I'm guessing a lot will be bad programming but that's why I'm here.</p>

<p>Also 1 question, when calling my methods I need to put the full path i.e. areaprog.areacode.. Do you know why this is? Code for both classes below:</p>

<p><strong>Main Program</strong></p>

<pre><code>package areaprog;

import java.util.Scanner;

public class mainprog {


    public static void main (String [] args){

        //Area Menu Selection
        System.out.println("What shape do you need to know the area of?\n" +
        "1: Square?\n" +
        "2: Rectangle?\n" +
        "3: Triangle?\n" +
        "4: Circle? \n" +
        "5: Exit\n"     
        );

        //User input for menu
        Scanner reader = new Scanner(System.in);
        System.out.println("Number: ");
        int input = reader.nextInt();
        reader.nextLine();

        //Depending on user selection, depends on what method is called using switch.
    Scanner scan = new Scanner(System.in);

        //Square selection
        if (input == 1){
            System.out.println("What is a length of 1 side of the Square?\n");
                double s1 = scan.nextInt();
                double SqAns = areaprog.areacode.square(s1);
            System.out.println("The area of you square is: " + SqAns);
        }

        //Rectangle selection    
            if (input == 2){
            System.out.println("What is the width of your rectangle?.\n");
                double r1 = scan.nextInt();
            System.out.println("What is the height of your rectangle?\n");
                double r2 = scan.nextInt();
                double RecAns = areaprog.areacode.rect(r1, r2);
            System.out.println("The area of your rectangle is: " + RecAns);    
            }
        //Triangle selection
        if (input == 3){
            System.out.println("What is the base length of the triangle?.");
                double t1 = scan.nextInt();
            System.out.println("What is the height of your triangle?");
                double t2 = scan.nextInt();
                double TriAns = areaprog.areacode.triangle(t1, t2);
            System.out.println("The area of your triangle is " + TriAns);
        }
        //Circle selection
        if (input == 4){
            System.out.println("What is the radius of your circle?.");
                double c1 = scan.nextInt();
                double CircAns = areaprog.areacode.circle(c1);
            System.out.println("The area of your circle is " + CircAns);    

        }
        //Exit application
        if (input == 5){
            System.out.println("Goodbye.");
        System.exit(0);
        }


    }

}
</code></pre>

<p><strong>Area Calculations</strong></p>

<pre><code>package areaprog;


public class areacode {

    public static double rect(double width, double height) {
        double a_value = width * height;

        return a_value;


    }

    public static double circle(double radius){
        double PI = Math.PI;
        double a_value = PI * Math.pow(radius, 2);

        return a_value;


    }

    public static double square(double side) {
        double a_value = Math.pow(side, 2);

        return a_value;


    }

    public static double triangle(double base , double height) {
        double a_value = (base/2)* height;

        return a_value;


    }
}
</code></pre>
