1014：与圆相关的计算

#include <iostream>
#include <iomanip>
using namespace std;
int main(){
	double r,d,l,s;
	cin>>r;
	d=2*r;
	l=3.14159*d;
	s=3.14159*r*r;
	cout<<fixed<<setprecision(4);
	cout<<d<<" "<<l<<" "<<s; 
	return 0;
}