Java: Check if three given side lengths can make a triangle or not

Last update on May 13 2025 13:00:21 (UTC/GMT +8 hours)

Check Triangle Validity

Write a Java program to check if three given side lengths (integers) can make a triangle or not.

Visual Presentation:

Sample Solution:

Java Code:

// Import Scanner class from java.util package for user input
import java.util.*;

// Main class for the solution
public class Solution {

    // Main method to execute the solution
    public static void main(String[] args) {
        // Create a Scanner object for user input
        Scanner in = new Scanner(System.in);

        // Prompt the user to input the first side of the triangle
        System.out.print("Input side1: ");
        // Read the user input as an integer
        int s1 = in.nextInt();

        // Prompt the user to input the second side of the triangle
        System.out.print("Input side2: ");
        // Read the user input as an integer
        int s2 = in.nextInt();

        // Prompt the user to input the third side of the triangle
        System.out.print("Input side3: ");
        // Read the user input as an integer
        int s3 = in.nextInt();

        // Display the result of the isValidTriangle function
        System.out.print("Is the said sides form a triangle: " + isValidTriangle(s1, s2, s3));
    }

    // Function to check if the given sides form a valid triangle
    public static boolean isValidTriangle(int a, int b, int c) {
        // Check the triangle inequality theorem to determine validity
        return (a + b > c && b + c > a && c + a > b);
    }
} 

Sample Output:

Input side1:  5
Input side2:  6
Input side3:  8
Is the said sides form a triangle: true 

Flowchart:

For more Practice: Solve these Related Problems:

• Write a Java program to determine if three given side lengths form an equilateral, isosceles, or scalene triangle.
• Write a Java program to verify if three given angles can constitute a valid triangle.
• Write a Java program to check the validity of a triangle when the side lengths are floating-point numbers.
• Write a Java program to validate a triangle and, if valid, compute its perimeter and area.

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