C语言：计算圆的周长和面积

#include
#define pi 3.14159
int main()
{
float r ,area , c ;
printf(“Input r:”);
scanf("%f",&r);
c = 2pir ;
area = pirr ;
printf(“circum = %.2f\n”,c);
printf(“area = %.2f\n”,area);
return 0;
}