\begin{equation*}

\mathfig{.73}{tempkw/zo2}

\end{equation*}

\begin{tikzpicture}

\newcommand{\rr}{6}

\newcommand{\vertex}{node[circle,fill=black,inner sep=1pt] {}}

\node(A) at (0,0) {

\begin{tikzpicture}

\node[red,left] at (0,0)  {$y$};

\draw (0,0) \vertex arc (-120:-105:\rr) node[red,below] {$a$} arc(-105:-90:\rr) \vertex node[red,below](x2) {$x$};

\draw (0,0) \vertex arc (120:105:\rr) node[red,above] {$a$} arc (105:90:\rr) \vertex node[red,above](x1) {$x$} -- (x2);

\begin{scope}

	\path[clip] (0,0) arc (-120:-60:\rr) arc (60:120:\rr);

	\foreach \x in {0,0.24,...,3} {

		\draw[green!50!brown] (\x,1) -- (\x,-1);

	}

\end{scope}

\draw[red, decorate,decoration={brace,amplitude=5pt}] ($(x1)+(0.2,-0.2)$) -- ($(x2)+(0.2,0.2)$) node[midway, xshift=0.7cm] {$x \times I$};

\end{tikzpicture}

};

\node(B) at (-4,-4) {

\begin{tikzpicture}

\node[red,left] at (0,0) {$y$};

\draw (0,0) \vertex 

	arc (120:105:\rr) node[red,above] {$a$}

	arc (105:90:\rr) node[red,above] {$x$} \vertex

	arc (90:75:\rr) node[red,above] {$x \times I$}

	arc (75:60:\rr) \vertex node[red,right] {$x$}

	arc (-60:-90:\rr) node[red,below] {$a$}

	arc (-90:-120:\rr);

\begin{scope}

	\path[clip] (0,0) arc (-120:-60:\rr) arc (60:120:\rr);

	\foreach \x in {0,0.48,...,9} {

		\draw[green!50!brown] (\x/4,1) -- (\x,-1);

	}

\end{scope}

\end{tikzpicture}

};

\node(C) at (4,-4) {

\begin{tikzpicture}[y=-1cm]

\node[red,left] at (0,0) {$y$};

\draw (0,0) \vertex 

	arc (120:105:\rr) node[red,below] {$a$}

	arc (105:90:\rr) node[red,below] {$x$} \vertex

	arc (90:75:\rr) node[red,below] {$x \times I$}

	arc (75:60:\rr) \vertex node[red,right] {$x$}

	arc (-60:-90:\rr) node[red,above] {$a$}

	arc (-90:-120:\rr);

\begin{scope}

	\path[clip] (0,0) arc (-120:-60:\rr) arc (60:120:\rr);

	\foreach \x in {0,0.48,...,9} {

		\draw[green!50!brown] (\x/4,1) -- (\x,-1);

	}

\end{scope}

\end{tikzpicture}

};

\draw[->] (A) -- (B);

\draw[->] (A) -- (C);

\end{tikzpicture}