提交时间:2023-01-31 13:39:47

运行 ID: 7003

#include<iostream> #include<iomanip> int main() { float 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; }