lr1

#include <iostream>
#include <cmath>
using namespace std;
class circle{
    double R, center_corner;
public:
    void circle_set(double radius, double corner){
    R = radius;
    center_corner = corner;
    }
    void up_set(){
        R+=5;
        center_corner+=20;
    }
    void square(){
        cout << "Square: " << M_PI * R * R * center_corner/360 << endl;
    }
    void lenght_arc(){
        cout << "Lenght arc: " << M_PI * R * center_corner/180 << endl;
    }
    void lenght_circle(){
        cout << "Lenght circle: " << 2 * M_PI * R << endl;
        cout << "Diameter: " << R * 2 << endl;
    }
    };
int main() {
    circle ci;
    ci.circle_set(5,60);
    ci.up_set();
    ci.square();
    ci.lenght_arc();
    ci.lenght_circle();
    return 0;
}