Check whether triangle is valid or not if sides are given

Last Updated : 10 Feb, 2025

Given three sides, check whether triangle is valid or not.

Examples:

Input : a = 7, b = 10, c = 5
Output : Valid
We can draw a triangle with the given three edge lengths.

Input : a = 1, b = 10, c = 12
Output : Invalid
We can not draw a triangle with the given three edge lengths.

Approach: A triangle is valid if sum of its two sides is greater than the third side. If three sides are a, b and c, then three conditions should be met.

(a + b) > c
(a + c) > b
(b + c) > a

Check whether triangle is valid or not if sides are given

C++

// C++ program to check if three sides form a triangle or not
#include <bits/stdc++.h>
using namespace std;

// function to check if three sider form a triangle or not
bool checkValidity(int a, int b, int c)
{
    if (a + b <= c || a + c <= b || b + c <= a)
        return false;
    else
        return true;
}

// Driver function
int main()
{
    int a = 7, b = 10, c = 5;
    if (checkValidity(a, b, c))
        cout << "Valid";
    else
        cout << "Invalid";
}

// This code is contributed by Aditya Kumar (adityakumar129)

// C program to check if three sides form a triangle or not
#include <stdio.h>
#include <stdbool.h>

// function to check if three sider form a triangle or not
bool checkValidity(int a, int b, int c)
{
    if (a + b <= c || a + c <= b || b + c <= a)
        return false;
    return true;
}

// Driver function
void main()
{
    int a = 7, b = 10, c = 5;
    if (checkValidity(a, b, c))
        printf("Valid");
    else
        printf("Invalid");
}

Java

// Java program to check validity of any triangle

public class GFG {
    // Function to calculate for validity
    public static int checkValidity(int a, int b, int c)
    {
        // check condition
        if (a + b <= c || a + c <= b || b + c <= a)
            return 0;
        else
            return 1;
    }

    // Driver function
    public static void main(String args[])
    {
        int a = 7, b = 10, c = 5;
        if ((checkValidity(a, b, c)) == 1)
            System.out.print("Valid");
        else
            System.out.print("Invalid");
    }
}

Python

# Python3 program to check if three
# sides form a  triangle or not 

# function to check if three sides 
# form a triangle or not 
def checkValidity(a, b, c): 
    
    # check condition 
    if (a + b <= c) or (a + c <= b) or (b + c <= a) :
        return False
    else:
        return True        

# driver code 
a = 7
b = 10
c = 5
if checkValidity(a, b, c):
    print("Valid") 
else:
    print("Invalid")

// C# program to check 
// validity of any triangle
using System;

class GFG {
    
    // Function to calculate for validity
    public static int checkValidity(int a, int b, 
                                    int c)
    {
        
        // check condition
        if (a + b <= c || a + c <= b || 
                            b + c <= a)
            return 0;
        else
            return 1;
    }

    // Driver code
    public static void Main()
    {
        int a = 7, b = 10, c = 5;
    
        // function calling and print output
        if ((checkValidity(a, b, c)) == 1)
          Console.Write("Valid");
        else
          Console.Write("Invalid");
        
    }
}

// This code is contributed by Nitin Mittal.

JavaScript

// Javascript program to check if three 
// sides form a triangle or not 

// function to check if three sider 
// form a triangle or not 
function checkValidity(a, b, c) 
{ 
    if (a + b <= c || a + c <= b || b + c <= a) 
        return false; 
    else
        return true; 
} 

// Driver function 
let a = 7, b = 10, c = 5; 
if (checkValidity(a, b, c)) 
    document.write("Valid"); 
else
    document.write("Invalid");

PHP

<?php
// PHP program to check if three
// sides form a triangle or not

// function to check if three sider
// form a triangle or not
function checkValidity($a, $b, $c)
{
    
    // check condition
    if ($a + $b <= $c ||
        $a + $c <= $b || 
        $b + $c <= $a)
        return false;
    else
        return true;
}

// Driver Code
$a = 7; 
$b = 10;
$c = 5;
if (checkValidity($a, $b, $c))
    echo "Valid";
else
    echo "Invalid";
?>

Output

Valid

Time Complexity: O(1)
Auxiliary Space: O(1)

Check whether right angled triangle is valid or not for large sides

Striver

Improve

Article Tags :

Practice Tags :

Check whether triangle is valid or not if sides are given

Similar Reads

Thank You!

What kind of Experience do you want to share?