\begin{center}
    \begin{tikzpicture}[scale=1.3333]
        \def\len{3}
        \draw[thick] (0, 0) -- (\len, 0) -- (\len, \len) -- (0, \len) -- (0, 0);
        \draw[thick] (0, 1) -- (2, 1) -- (2, \len);
        \draw[thick] (1, 1) -- (1, 0);
        \draw[thick] (2, 1) -- (2, 0);
        \draw[thick] (2, 1) -- (\len, 1);
        \draw[thick] (2, 2) -- (\len, 2);
        \draw (1, 2) node{$1$};
        \draw (2.5, 2.5) node{$2$};
        \draw (2.5, 1.5) node{$3$};
        \draw (2.5, 0.5) node{$4$};
        \draw (1.5, 0.5) node{$5$};
        \draw (0.5, 0.5) node{$6$};
    \end{tikzpicture}
    \begin{tikzpicture}
        \def\len{4}
        \draw[thick] (0, 0) -- (\len, 0) -- (\len, \len) -- (0, \len) -- (0, 0);
        \draw[thick] (0, 2) -- (\len, 2);
        \draw[thick] (2, 0) -- (2, \len);
        \draw[thick] (0, 3) -- (2, 3);
        \draw[thick] (1, 2) -- (1, \len);
        \draw (0.5, 3.5) node{$1$};
        \draw (1.5, 3.5) node{$2$};
        \draw (0.5, 2.5) node{$3$};
        \draw (1.5, 2.5) node{$4$};
        \draw (3, 3) node{$5$};
        \draw (3, 1) node{$6$};
        \draw (1, 1) node{$7$};
    \end{tikzpicture}
    \begin{tikzpicture}
        \def\len{4}
        \draw[thick] (0, 0) -- (\len, 0) -- (\len, \len) -- (0, \len) -- (0, 0);
        \draw[thick] (0, 1) -- (3, 1) -- (3, \len);
        \draw[thick] (1, 1) -- (1, 0);
        \draw[thick] (2, 1) -- (2, 0);
        \draw[thick] (3, 1) -- (3, 0);
        \draw[thick] (3, 1) -- (\len, 1);
        \draw[thick] (3, 2) -- (\len, 2);
        \draw[thick] (3, 3) -- (\len, 3);
        \draw (1.5, 2.5) node{$1$};
        \draw (3.5, 3.5) node{$2$};
        \draw (3.5, 2.5) node{$3$};
        \draw (3.5, 1.5) node{$4$};
        \draw (3.5, 0.5) node{$5$};
        \draw (2.5, 0.5) node{$6$};
        \draw (1.5, 0.5) node{$7$};
        \draw (0.5, 0.5) node{$8$};
    \end{tikzpicture}
\end{center}