Задачи
Окружность
pi = 3.141592653589793
include <bits/stdc++.h>
using namespace std; int main () { double p,r; cin>>r; p=3.14159265; double l,s; l=2pr; s=pow(r,2)*p; cout.precision(4); cout<<fixed<<l<<' '<<s;
} //by Galata_ing
pi = 3.141592653589793
using namespace std; int main () { double p,r; cin>>r; p=3.14159265; double l,s; l=2pr; s=pow(r,2)*p; cout.precision(4); cout<<fixed<<l<<' '<<s;
} //by Galata_ing