include<stdio.h>
difine PI 3.14
double calculateSquare(int radius);
int main()
{
int cRadius=0;
double square=0.0;
printf("請輸入圓的半徑:\n");
scanf("%d",&cRadius);
square=calculateSquare(cRadius);
printf("圓的面積是:%f\n",square);
return 0;
}
double calculateSquare(int radius)
{
double result=PIradiusradius;
return result;
