#include"stdio.h" void main() { float r,L,S; printf("请输入半径:"); scanf("%f",&r); L=2*3.14*r; S=3.14*r*r; printf("周长%.2f,面积%.2f",L,S);}
#define PI 3.14void main() {float r,l,s;scanf("%f",&r);l=2*PI*r;s=(r*r)*PI;printf("l=%f.s=%f",l,s);getch();}
#include <stdio.h>#define PI 3.1415int main(void){ double bj; scanf("%lf", &bj); printf("zc: %f, mj: %f", 2 * PI * bj, PI * bj * bj); return 0;}