提交时间:2024-09-22 22:21:37

运行 ID: 51633

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