\begin{tikzpicture} \tikzset{ arrowMe/.style={postaction=decorate, decoration={markings, mark=at position .6 with {\arrow[very thick]{#1}} } }} \fill[color=blue!20](0,0) rectangle (2,2); \draw (0,0) rectangle (2,2); \draw[arrowMe=stealth](2,0)--node[below]{\(b_2\)} (0,0); \draw[arrowMe=stealth](2,2)--node[above]{\(b_2\)} (0,2); \draw[arrowMe=stealth](0,0)--node[left]{\(a_2\)} (0,2); \draw[arrowMe=stealth](2,0)--node[right]{\(a_2\)} (2,2); \draw[fill=white, arrowMe=stealth](2,0) to [bend left=50] (1.4,.6) node[left=-2pt]{\(c\)}; \draw[fill=white](1.4,.6) to [bend left=50] (2,0); \begin{scope}[xshift=3cm] \fill[color=blue!20](0,0) rectangle (2,2); \draw (0,0) rectangle (2,2); \draw[arrowMe=stealth](2,0)--node[right]{\(b_1\)} (2,2); \draw[arrowMe=stealth](0,0)--node[left]{\(b_1\)} (0,2); \draw[arrowMe=stealth](0,0)--node[below]{\(a_1\)} (2,0); \draw[arrowMe=stealth](0,2)--node[above]{\(a_1\)} (2,2); \draw[fill=white, arrowMe=stealth](0,0) to [bend right=50] (.6,.6) node[right=-2pt]{\(c\)}; \draw[fill=white](.6,.6) to [bend right=50] (0,0); \end{scope} \draw (2.5,-.5) node{(a)}; \begin{scope}[xshift=.8cm, yshift=-2.5cm] \def\r{1.4} \tkzDefPoint(18:\r){v1}\tkzDefPoint(90:\r){v2}\tkzDefPoint(162:\r){v3}\tkzDefPoint(234:\r){v4}\tkzDefPoint(306:\r){v5} \fill[color=blue!20](v1)--(v2)--(v3)--(v4)--(v5)--cycle; \draw[arrowMe=stealth](v1)--node[above]{\(a_2\)}(v2); \draw[arrowMe=stealth](v2)--node[above]{\(b_2\)}(v3); \draw[arrowMe=stealth](v4)--node[left]{\(a_2\)}(v3); \draw[arrowMe=stealth](v5)--node[below]{\(b_2\)}(v4); \draw[arrowMe=stealth](v5)--node[right]{\(c\)}(v1); \begin{scope}[xshift=3.5cm] \tkzDefPoint(18:\r){v1}\tkzDefPoint(90:\r){v2}\tkzDefPoint(162:\r){v3}\tkzDefPoint(234:\r){v4}\tkzDefPoint(306:\r){v5} \fill[color=blue!20](v1)--(v2)--(v3)--(v4)--(v5)--cycle; \draw[arrowMe=stealth](v2)--node[above]{\(a_1\)}(v1); \draw[arrowMe=stealth](v3)--node[above]{\(b_1\)}(v2); \draw[arrowMe=stealth](v4)--node[left]{\(c\)}(v3); \draw[arrowMe=stealth](v4)--node[below]{\(a_1\)}(v5); \draw[arrowMe=stealth](v5)--node[right]{\(b_1\)}(v1); \end{scope} \draw (1.7,-1.8) node{(b)}; \end{scope} \begin{scope}[xshift=9cm] \def\r{1.7} \tkzDefPoint(0:\r){v1}\tkzDefPoint(45:\r){v2}\tkzDefPoint(90:\r){v3}\tkzDefPoint(135:\r){v4}\tkzDefPoint(180:\r){v5}\tkzDefPoint(225:\r){v6}\tkzDefPoint(270:\r){v7}\tkzDefPoint(315:\r){v8} \fill[color=blue!20](v1)--(v2)--(v3)--(v4)--(v5)--(v6)--(v7)--(v8)--cycle; \draw[dashed,arrowMe=stealth] (v7)--node[right]{\(c\)} (v3); \draw[arrowMe=stealth](v3)--node[above]{\(a_2\)}(v4); \draw[arrowMe=stealth](v4)--node[left]{\(b_2\)}(v5); \draw[arrowMe=stealth](v6)--node[left]{\(a_2\)}(v5); \draw[arrowMe=stealth](v7)--node[below]{\(b_2\)}(v6); \draw[arrowMe=stealth](v7)--node[below]{\(a_1\)}(v8); \draw[arrowMe=stealth](v8)--node[right]{\(b_1\)}(v1); \draw[arrowMe=stealth](v2)--node[right]{\(a_1\)}(v1); \draw[arrowMe=stealth](v3)--node[above]{\(b_1\)}(v2); \draw (0,-2.2) node{(c)}; \end{scope} \end{tikzpicture}