#include <stdio.h>
#include <stdlib.h>
#define PI 3.14159
int main()
{
double R,l,s;
scanf("%lf",&R);
l = 2 * PI * R;
s = PI * R * R;
printf(“圆的周长为:%lf\n”,l);
printf(“圆的面积为:%lf”,s);
system(“pause”);
return 0 ;
}
来源:CSDN
作者:K2MnO2
链接:https://blog.csdn.net/Polary1/article/details/104560671