提交时间:2023-08-05 18:40:11

运行 ID: 24127

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