提交时间:2023-01-24 13:17:02

运行 ID: 6463

#include <iostream> #include <iomanip> using namespace std; int main() { double r; cin >> r; cout << fixed << setprecision(4) << 2*r; cout << " "; cout << fixed << setprecision(4) << 2*3.14159*r; cout << " "; cout << fixed << setprecision(4) << 3.14159*r*r; return 0; }