[code language=”c”]
#include <stdio.h>
#include <time.h>
#include <stdlib.h>
int main() {
int input;
printf("Please input the radius! \n");
scanf("%d",&input);
const float PI=3.14159;
printf("The area=%f\n",PI*input*input);
system("pause");
return 0;
}
[/code]