Question

用C语言编程输入圆的半径输出圆的周长和面积

Answer 1

#include<stdio.h>
int main()
{float r,C,S;
scanf("%f",&r);
C=2*3.1416*r;
S=3.1416*r*r;
printf("周长=%f\n面积=%f\n",C,S);
return 0;
}