I have this program that I need help with. Basically its a program where a user is prompted to enter the length of all three sides of a triangle and the program calculates the area by herons formula and can tell if the triangle is equilateral or Pythagorean. I am having trouble entering a formula to where all three enter sides cant possibly be a triangle. Here is my Program. I need help where the '?' is stated.

import java.util.Scanner;

public class Triangle {

public static void main(String[] args){

double a;

double b;

double c;

double s;

double x;

double area;

Scanner input = new Scanner(System.in);

System.out.println("Welcome to the Triangle Calculation Program");

System.out.print ("Enter length of side one => ");

a = input.nextDouble();

System.out.print ("Enter length of side two => ");

b = input.nextDouble();

System.out.print ("Enter length of side three => ");

c = input.nextDouble();

System.out.println("Your triangle has an area of " + getArea(a,b,c));

if ( (a == b) && (b == c) ) {

System.out.println("This was a Equilateral triangle");

}

else if ( ( a*a + b*b == c*c ) || (b*b + c*c == a*a) || (c*c + a*a == b*b )) {

System.out.println("This was a Pythagorean triangle");

}

else if ( ( ? ) ) {

System.out.println("Sorry- not a valid triangle");

}

}

public static double getArea(double a, double b, double c) {

double s = (a + b + c)/2.0;

double x = ((s) * (s-a) * (s-b) * (s-c));

double area = Math.sqrt(x);

return area;

}

}