Triangle-Java

import java.util.Scanner;
class TriangleCalc {
  public static void main(String[] args){
     Scanner scan = new Scanner(System.in);
     double a, b, c, p, P, S;
     System.out.print("Enter a: ");
     a = scan.nextDouble();
     System.out.print("Enter b: ");
     b = scan.nextDouble();
     System.out.print("Enter c: ");
     c = scan.nextDouble();
    if (a <= 0 || b <= 0 || c <= 0 || a + b <= c || a + c <= b || b + c <= a){
       System.out.println("Invalid triangle!");
       return;
     }

     P = a + b + c;
     p = P / 2;
     S = Math.sqrt(p*(p-a)*(p-b)*(p-c));
     System.out.printf("P = %.2f\n", P);
     System.out.printf("S = %.2f\n", S);
  }
}