提交时间:2023-12-28 20:32:22

运行 ID: 35160

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