import java.io.*;

/**
 * refector
 * make the code to calculate the area of a circle reusable
 */

public class Circle4 {

  public double getArea(double radius) {
    return Math.PI * radius * radius;
  }

  public static void main(String argv[]) throws IOException {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    System.out.print("Please enter the radius of the circle: ");
    String input = br.readLine();
    double radius = Double.parseDouble(input);

    // getArea() is not static so create an instance then call it
    Circle4 c = new Circle4();
    double area = c.getArea(radius);

    // print the result
    System.out.println("The area of a circle with radious " + radius + " is: " + area);
  }
}