#include<stdio.h>
#define PI 3.14159
float Cheng(long a)
{
return(PI*a*a);
}
float Zhou(long b)
{
return(2*PI*b);
}
main()
{
float R;
float aaa ,bbb ;
printf("Please input a number:");
scanf("%f",&R);
aaa=Cheng(R);
bbb=Zhou(R);
printf("aaa=%.15f\n",aaa);
printf("bbb=%.15f\n",bbb);
}