Example: Triangle Angle Validator in C++

// Triangle Angle Validator
#include <iostream>

int main() {
    // Step 1: Declare three variables to store the angles
    double angle1, angle2, angle3;

    // Step 2: Prompt the user to enter the three angles
    std::cout << "Enter the first angle: ";
    std::cin >> angle1;

    std::cout << "Enter the second angle: ";
    std::cin >> angle2;

    std::cout << "Enter the third angle: ";
    std::cin >> angle3;

    // Step 3: Calculate the sum of the three angles
    double sumOfAngles = angle1 + angle2 + angle3;

    // Step 4: Check if the sum is approximately 180 and all angles are positive
    // Using a small epsilon for floating-point comparison is good practice,
    // but for exact integer angles, direct comparison might suffice.
    // For general floating-point input, comparison with a tolerance is better.
    // Here we'll assume precise input for simplicity.
    if (sumOfAngles == 180.0 && angle1 > 0 && angle2 > 0 && angle3 > 0) {
        std::cout << "The entered angles (" << angle1 << ", " << angle2 << ", " << angle3 << ") form a valid triangle." << std::endl;
    } else {
        std::cout << "The entered angles (" << angle1 << ", " << angle2 << ", " << angle3 << ") do not form a valid triangle." << std::endl;
        if (sumOfAngles != 180.0) {
            std::cout << "Reason: Sum of angles is " << sumOfAngles << ", which is not 180." << std::endl;
        }
        if (angle1 <= 0 || angle2 <= 0 || angle3 <= 0) {
            std::cout << "Reason: One or more angles are not positive." << std::endl;
        }
    }

    return 0;
}