#include <iostream> using namespace std; int main() { cout << 3.1415926 * 1 * 1 << endl; cout << 3.1415926 * 3 * 3 << endl; cout << 3.1415926 * 5 * 5 << endl; cout << 3.1415926 * 7 * 7 << endl; cout << 3.1415926 * 9 * 9 << endl; return 0; }