提交时间:2023-12-21 19:20:41

运行 ID: 34410

#include<iostream> using namespace std; int main() { float r; cin>>r; float a=2*r; float b=2*3.14159*r; float c=3.14159*r*r; printf("%.4f",a); cout<<" "; printf("%.4f",b); cout<<" "; printf("%.4f",c); return 0; }