一个小程序的问题

jc_zhong

#include<stdio.h>
#include<math.h>
#define PI 3.14
double find_circum(double);
double find_area(double);
int
main(void)
{
        double radius;
        double circum;
        double area;
    printf("lease enter the radius >");
    scanf("%f",&radius);
    circum=find_circum(radius);
    area=find_area(radius);
    printf("The circum is %f.\n",circum);
    printf("The area is %f.\n",area);
    return 0;
}
double
find_circum(double r)
{
        return(2.0*PI*r);
}
double
find_area(double r)
{
        return(pow(r,2)*PI);
}

一段简单的代码如上，为何输出结果总是零？唉...

8pm

%f -> %lf

jc_zhong

哦～粗心了，谢谢！