提交时间:2024-09-21 18:25:04

运行 ID: 51417

#include <bits/stdc++.h> using namespace std; int main() { double r; cin>>r; double d=2*r; double C=6.28318*r; double S=3.14159*r*r; cout<<fixed<<setprecision(4)<<d<<C<<S<<endl; }