# How to Check If a Triangle Can be Formed in Java

The sides of a triangle is constrained by the rule that the sum of any of its two sides is always bigger than the third side. Using this rule, we can find whether 3 sides given for a triangle is valid or not. The following sample Java program checks whether the given 3 sides can form a valid triangle.

import java.util.Scanner; /** * Validates whether the given 3 sides can form a triangle or not. * @author jj */ public class ValidTriangle { public static void main(String[] args) { Scanner sn = new Scanner(System.in); System.out.println("Enter length of first side of triangle:"); double a = sn.nextDouble(); System.out.println("Enter length of second side of triangle:"); double b = sn.nextDouble(); System.out.println("Enter length of third side of triangle:"); double c = sn.nextDouble(); ValidTriangle vt = new ValidTriangle(); if(vt.isTriangleValid(a, b, c)) { System.out.println("Sides entered can form a triangle!"); }else { System.out.println("Sides entered cannot form a triangle!"); } } /** * Checks whether the 3 sides can form a triangle * The sum of any two sides must be greater than the other side * @param a * @param b * @param c * @return */ private boolean isTriangleValid(double a, double b, double c) { if((a+b)>c && (a+c)>b && (b+c)>a) { return true; }else { return false; } } }