Some commuting diagrams.

A commuting "line" (aka a morphism)

X \overset{f}{\rightarrow}Y
$$X \overset{f}{\rightarrow}Y$$

A commuting "triangle"

\begin{matrix}
X & \overset{f}{\rightarrow } &Y \\
id_x \downarrow & & \downarrow h\\
X &\underset{g}{\rightarrow} &Z
\end{matrix}
$$\begin{matrix} X & \overset{f}{\rightarrow } &Y \\ id_x \downarrow & & \downarrow h\\ X &\underset{g}{\rightarrow} &Z \end{matrix}$$

A commuting square

\begin{matrix}
X & \overset{f}{\rightarrow } &W \\
e \downarrow & & \downarrow h\\
Y &\underset{g}{\rightarrow} &Z
\end{matrix}
$$\begin{matrix} X & \overset{f}{\rightarrow } &W \\ e \downarrow & & \downarrow h\\ Y &\underset{g}{\rightarrow} &Z \end{matrix}$$

A commuting "pentagon"

\begin{matrix}
X & \overset{f}{\rightarrow }& S & \overset{l}{\rightarrow } &W \\
id_x \downarrow & & & & \downarrow h\\
X &\underset{g}{\rightarrow}&T&\underset{k}{\rightarrow} &Z
\end{matrix}
$$\begin{matrix} X & \overset{f}{\rightarrow }& S & \overset{l}{\rightarrow } &W \\ id_x \downarrow & & & & \downarrow h\\ X &\underset{g}{\rightarrow}&T&\underset{k}{\rightarrow} &Z \end{matrix}$$

A commuting "hexagon"

\begin{matrix}
X & \overset{f}{\rightarrow }& S & \overset{l}{\rightarrow } &W \\
e \downarrow & & & & \downarrow h\\
Y &\underset{g}{\rightarrow}&T&\underset{k}{\rightarrow} &Z
\end{matrix}
$$\begin{matrix} X & \overset{f}{\rightarrow }& S & \overset{l}{\rightarrow } &W \\ e \downarrow & & & & \downarrow h\\ Y &\underset{g}{\rightarrow}&T&\underset{k}{\rightarrow} &Z \end{matrix}$$

A commuting "\$$(2n+1)-\$$gon"

\begin{matrix}
X & \overset{f}{\rightarrow }& S & \overset{l}{\rightarrow }&R&\overset{\cdots}{\rightarrow }&W \\
id_x \downarrow & & & & & & \downarrow h\\
X &\underset{g}{\rightarrow}&T&\underset{k}{\rightarrow}&Q&\underset{\cdots}{\rightarrow} &Z
\end{matrix}
$$\begin{matrix} X & \overset{f}{\rightarrow }& S & \overset{l}{\rightarrow }&R&\overset{\cdots}{\rightarrow }&W \\ id_x \downarrow & & & & & & \downarrow h\\ X &\underset{g}{\rightarrow}&T&\underset{k}{\rightarrow}&Q&\underset{\cdots}{\rightarrow} &Z \end{matrix}$$

A commuting "\$$(2n)-\$$gon"

\begin{matrix}
X & \overset{f}{\rightarrow }& S & \overset{l}{\rightarrow }&R&\overset{\cdots}{\rightarrow }&W \\
e \downarrow & & & & & & \downarrow h\\
Y &\underset{g}{\rightarrow}&T&\underset{k}{\rightarrow}&Q&\underset{\cdots}{\rightarrow} &Z
\end{matrix}
$$\begin{matrix} X & \overset{f}{\rightarrow }& S & \overset{l}{\rightarrow }&R&\overset{\cdots}{\rightarrow }&W \\ e \downarrow & & & & & & \downarrow h\\ Y &\underset{g}{\rightarrow}&T&\underset{k}{\rightarrow}&Q&\underset{\cdots}{\rightarrow} &Z \end{matrix}$$