Pole i Obwód koła

// poleobwodkolo.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include <conio.h>
#define _USE_MATH_DEFINES
#include <math.h>


int main()
{
    float r, y, z;
    M_PI;
    printf("+-----------------------------------------+\n");
    printf("|  Program obliczajacy pole i obwod kola  |\n");
    printf("|                        made by Peterzig |\n");
    printf("+-----------------------------------------+\n");
    printf("Podaj promien kola r = ");
    scanf("%f", &r);
    y = M_PI*r*r;
    z = 2 * M_PI*r;
    printf("+--------------------------------+\n");
    printf("|       Pole     |      Obwod    |\n");
    printf("+--------------------------------+\n");
    printf("|           %5.3f|          %5.3f|\n", y,z );
    printf("+--------------------------------+\n");
    _getch();
    return 0;
}