/* Regular polygon - a polygon in which all sides are equal. This program shows value of angles of input regular polygon and its' perimeter and area. You need to enter number of polygons' angles and length of its' side. Example of input: 4 5 (4-angled regular polygon with length of side 5) */ #include #include #include using namespace std; class RegularPolygon { private: int m_iAnglesCount; double m_dSideLength; public: RegularPolygon() { } ~RegularPolygon() { } void Init(string s) { stringstream ss(s); ss >> m_iAnglesCount >> m_dSideLength; if (ss.fail()) { throw "Wrong input\n"; } if (m_iAnglesCount < 3) { throw "Number of angles must be bigger than 2\n"; } if (m_dSideLength <= 0.0) { throw "Side length must be bigger then 0\n"; } } int GetAnglesCount() { return m_iAnglesCount; } double GetSideLength() { return m_dSideLength; } double DegreesAngle() { return 180*(m_iAnglesCount-2)/(double)m_iAnglesCount; } double RadiansAngle() { return M_PI*DegreesAngle()/180.0; } double Perimeter() { return m_iAnglesCount*m_dSideLength; } double Area() { return (pow(m_dSideLength,2)*m_iAnglesCount)/(4*tan(M_PI/m_iAnglesCount)); } }; int main() { string s; getline(cin,s); RegularPolygon polygon; try { polygon.Init(s); cout << "Parameters of regular " << polygon.GetAnglesCount() << "-angled polygon with side length " << polygon.GetSideLength() << ":\n" << "-> Angle: " << polygon.DegreesAngle() << "° (" << polygon.RadiansAngle() << " rad)\n" << "-> Perimeter: " << polygon.Perimeter() << '\n' << "-> Area: " << polygon.Area() << '\n'; } catch(const char* err) { cerr << err; } return 0; }

Regular polygons (class method)