Triagolnik

#include <iostream>
#include <cmath>

using namespace std;

bool   canBeFormed       (double, double, double); // Proveruva dali mozhe da se formira triagolnik koristejkji neravenstvo.
double calculateArea     (double, double, double); // Presmetuva ploshtina po Heronova formula.
double calculatePerimeter(double, double, double); // Presmetuva perimetar.

int main()
{
    double a, b, c; // Strani.
    cout << "Vneste ja prvata strana na triagolnikot: ";
    cin >> a;
    cout << "Vneste ja vtorata strana na triagolnikot: ";
    cin >> b;
    cout << "Vneste ja tretata strana na triagolnikot: ";
    cin >> c;

    if (canBeFormed(a, b, c))
    {
        cout << "\nStranite so dolzhina " << a << ", " << b << " i " << c << " edinici mozhe da formiraat triagolnik." << endl
             << "Negoviot perimetar iznesuva "   << calculatePerimeter(a, b, c) << ", "        << endl
             << "a negovata ploshtina iznesuva " << calculateArea(a, b, c)      << " edinici." << endl;
    }
    else
    {
        cout << "\nStranite so dolzhina " << a << ", " << b << " i " << c << " edinici ne mozhe da formiraat triagolnik." << endl;
    }
    return 0;
}

bool canBeFormed(double a, double b, double c)
{
    return ( (a + b > c) && (a + c > b) && (b + c > a) );
}

double calculatePerimeter(double a, double b, double c)
{
    return (a + b + c);
}

double calculateArea(double a, double b, double c) // Heronova formula.
{
    double s = calculatePerimeter(a, b, c) / 2.; // Poluperimetar.
    return sqrt(s * (s - a) * (s - b) * (s - c));
}