提交时间:2020-07-28 19:24:36

运行 ID: 5279

#include<bits/stdc++.h> using namespace std; int main(){ double r,pi,d,c,s; cin>>r; pi=3.14159; d=r*2; c=r*pi*2; s=r*r*pi; cout<<fixed<<setprecision(4)<<d<<" "<<c<<" "<<s; return 0; }