#include <bits/stdc++.h>. using namespace std; int main (){ double a=1 b=3 c=5 d=7 e=9 cout 3.1415926*1*1 cout 3.1415926*3*3 cout 3.1415926*5*5 cout 3.1415926*7*7 cout 3.1415926*9*9 return 0; }