提交时间:2023-02-04 10:42:19

运行 ID: 7486

#include<bits/stdc++.h> //E using namespace std; int main() { double a; cin>>a; cout<<fixed<<setprecision(4)<<2*a<<" "; cout<<fixed<<setprecision(4)<<3.14159*2*a<<" "; cout<<fixed<<setprecision(4)<<a*a*3.14159; return 0; }