JAVA week 1 Program question 1

Java Week 1:Q1

//Complete the code segment to find the perimeter and area of a circle given a value of radius.
You should use Math.PI constant in your program.
If radius is zero or less than zero then print " please enter non zero positive number ".

import java.util.Scanner; 

public class Exercise1_1

 {

       public static void main(String[] args) 

{

       Scanner s = new Scanner(System.in);
       double radius= s.nextDouble();
       double perimeter;
       double area;
{
  if (radius<=0)
    System.out.print("please enter non zero positive number ");
}

//Calculate the perimeter
perimeter=2*Math.PI*radius;

  //Calculate the area
area=(Math.PI)*radius*radius;

System.out.print(perimeter+"\n"+area);

}
}