If we divide every of the unit squares into 9 smaller squares and label every each of them as $A,B,C,D,E,F,G,H,I$ for the lines (top to bottom) and 1 to 9 for the columns, then we can find the following example: The first figure consists of squares $D2,D1,E1,F1,F2,F3,F4,F5,G4,H4,H5,H6,I4,I5,I6$. The second one is basically reflect the first one through the center of the cross (squares $A4,A5,A6,B4,B5,B6,C6,D5$ to $D9,E9, F8, F9$). The last polygon is formed by the rest of the squares: \begin{tabular}{|c|c|c|c|c|c|c|c|c|c|} \hline & 1 & 2 & 3 & 4 & 5 & 6 & 7 & 8 & 9\\ \hline A & & & & $\bigstar$ & $\bigstar$ & $\bigstar$ & & &\\ \hline B & & & & $\bigstar$ & $\bigstar$ & $\bigstar$ & & &\\ \hline C & & & & $\checkmark$ & $\checkmark$ & $\bigstar$ & & &\\ \hline D & $\spadesuit$ & $\spadesuit$ & $\checkmark$ & $\checkmark$ & $\bigstar$ & $\bigstar$ & $\bigstar$ & $\bigstar$ & $\bigstar$\\ \hline E & $\spadesuit$ & $\checkmark$ & $\checkmark$ & $\checkmark$ & $\checkmark$ & $\checkmark$ & $\checkmark$ & $\checkmark$ & $\bigstar$\\ \hline F & $\spadesuit$ & $\spadesuit$ & $\spadesuit$ & $\spadesuit$ & $\spadesuit$ & $\checkmark$ & $\checkmark$ & $\bigstar$ &$\bigstar$\\ \hline G & & & & $\spadesuit$ & $\checkmark$ & $\checkmark$ & & & \\ \hline H & & & & $\spadesuit$ & $\spadesuit$ & $\spadesuit$ & & &\\ \hline I & & & & $\spadesuit$ & $\spadesuit$ & $\spadesuit$ & & &\\ \hline \end{tabular}