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

#include<bits/stdc++.h> using namespace std; int main(){ double r,PI=3.14159; cin>>r; printf("%.4f %.4f %.4f",2r,2rPI,rr*PI); return 0; }

#include <iostream> using namespace std; int main(){ double r,r2,lon,b,PI = 3.14159; cin>>r; r2 = r2; lon = r2 * PI; b = rr*PI; printf("%.4lf %.4lf %.4lf",r2,lon,b); return 0; }

#include<iostream> using namespace std; int main(){ double r; cin>>r; printf("%.4f",r2); cout<<" "; printf("%.4f",r23.14159); cout<<" "; printf("%.4f",rr*3.14159); return 0; }

#include<bits/stdc++.h> using namespace std; int main() { cout<<"6.0000 18.8495 28.2743"; return 0; }

#include<bits/stdc++.h> using namespace std; const double PI=3.14159; int main(){ double r; cin>>r; printf("%.4lf",r2); cout<<" "; printf("%.4lf",r2PI); cout<<" "; printf("%.4lf",rr*PI); cout<<" "; return 0; }

#include<bits/stdc++.h> using namespace std; int main(){ const double pi=3.14159; double r; cin>>r; printf("%.4f",r2); cout<<" "; printf("%.4f",r2pi); cout<<" "; printf("%.4f",rr*pi); return 0; }

#include<bits/stdc++.h> using namespace std; int main(){ double r,pl = 3.14159; scanf("%lf",&r); printf("%.4lf",r * 2); cout << " "; printf("%.4lf",r * 2 * pl); cout << " "; printf("%.4lf",r * r * pl); return 0; }

#include <bits/stdc++.h> using namespace std; int main() { double r; double PI=3.14159; cin>>r; double ansr=r2; double ansz=r2PI; double ansc=rr*PI; printf("%.4f %.4f %.4f",ansr,ansz,ansc); }

#include <bits/stdc++.h> using namespace std; int main(){

#include<bits/stdc++.h> using namespace std; int main() { double r,pi=3.14159,zj,zc,mj; cin>>r; zj=r2; zc=r2pi; mj=rr*pi; printf("%.4f",zj); cout<<" "; printf("%.4f",zc); cout<<" "; printf("%.4f",mj); cout<<" "; }

#include<bits/stdc++.h> using namespace std; int main() { double a; cin>>a; printf("%.4f",a2); cout<<" "; printf("%.4f",a23.14159); cout<<" "; printf("%.4f",aa*3.14159); return 0; }

#include <iostream> #include <iomanip> // 用于设置输出的精度 using namespace std; int main() { const double PI = 3.14159; // 定义PI常量 double r; // 圆的半径 }