提交时间:2023-11-19 13:14:20

运行 ID: 31496

#include<iostream> #include<iomanip> using namespace std; const double PI=3.14159; int main() { double r,d,c,s; cin>>r; d=r*2; c=2*PI*r; s=PI*r*r; cout<<fixed<<setprecision(4)<<d<<" "<<c<<" "<<s<<endl; return 0; }