提交时间:2023-01-20 17:42:10
运行 ID: 6126
#include<bits/stdc++.h> using namespace std; int main() { double r,d,c,s; cin>>r; d=2*r; cout<<fixed<<setprecision(4)<<d<<endl; c=3.14159*d; cout<<fixed<<setprecision(4)<<c<<endl; s=3.14159*r*r; cout<<fixed<<setprecision(4)<<s; return 0; }