提交时间:2023-01-31 13:41:28
运行 ID: 7005
#include<iostream> #include<iomanip> using namespace std; int main() { float r; cin >> r; cout << fixed << setprecision(4) << 2*r; cout << " "; cout << fixed << setprecision(4) << 3.14159*2*r; cout << " "; cout << fixed << setprecision(4) << 3.14159*r*r; return 0; }