import java.util.Scanner;
class AreaPerimeterTriangle
{
 public static void main(String args[])
 {
  Double tside1,tside2,tside3, ts;
  Scanner sc=new Scanner(System.in);
  System.out.println("Enter lengths of sides of your triangle ");
  System.out.print("Side 1: ");
  tside1=sc.nextDouble();
  System.out.print("Side 2: ");
  tside2=sc.nextDouble();
  System.out.print("Side 3: ");
  tside3=sc.nextDouble();
  if (tside1 > 0.0 && tside2 > 0.0 && tside3 > 0.0) {
   ts = (tside1+tside2+tside3) / 2.0; // Source: http://mste.illinois.edu/dildine/heron/triarea.html
   System.out.println("The triangle perimeter is " + (tside1 + tside2 + tside3) + " and the area is " + Math.pow((ts*(ts - tside1)*(ts - tside2)*(ts - tside3)), 0.5));
  } else {
   System.out.println("This is invalid data for a triangle.");
  }
  return;
 }
}