정올 572 : 함수1-자가진단2

My Solution

#include<stdio.h>
void area(int radius){
    float r_area;
    r_area  =radius*radius*3.14;
    printf("%.2f",r_area);
}
int main(void){
    int radius;
    scanf("%d",&radius);
    area(radius);
    return 0;
}