CircleComputation.java

public class CircleComputation {

    public static void main(String[] args) {
        double radius, area, circumference, diameter;   // A "double" holds floating-point number with an optional fractional part.
        final double PI = 3.1416; // Declare a double to hold PI.  // Declare as "final" to specify that its value cannot be changed (i.e. constant).          
        radius = 1.2;
        area = PI * radius * radius; // the * is to multiple, stupid!
        diameter = 2.0 * radius;
        circumference = PI * diameter;

        System.out.print("The radius is ");
        System.out.println(radius);  // Print the value stored in the variable

        System.out.print("The area is ");
        System.out.println(area);

        System.out.print("The diameter is ");
        System.out.println(diameter);

        System.out.print("The circumference is ");
        System.out.println(circumference);
    }
}