% complile with »pdflatex«
\documentclass[tikz,convert=pdf2svg]{standalone}
\begin{document}
 \begin{tikzpicture}
  \pgfmathsetmacro{\radius}{2.1};
  \pgfmathsetmacro{\DBG}{38};
  \coordinate (A) at (0:\radius);
  \coordinate (B) at (0,0);
  \coordinate (C) at (180:\radius);
  \coordinate (D) at (90:\radius);
  \coordinate (E) at (-90:\radius);
  \coordinate (F) at (90-\DBG:\radius);
  \coordinate (G) at (90+\DBG:\radius);
  \coordinate (M) at  (G|-B);
  \coordinate (N) at  (F|-B);
  \coordinate (P) at (-75:\radius);
  \coordinate (O) at  (P|-B);
  \draw (B) circle[radius=\radius];
  \draw (A) -- (C);
  \draw (E) -- (D);
  \draw (F) -- (N);
  \draw (G) -- (M);
  \draw (P) -- (O);
  \draw (A) +(0:0.2) node{$a$};
  \draw (B) +(-125:0.2) node{$b$};
  \draw (C) +(180:0.2) node{$c$};
  \draw (D) +(90:0.2) node{$d$};
  \draw (E) +(-90:0.2) node{$e$};
  \draw (F) +(90-\DBG:0.2) node{$f$};
  \draw (G) +(90+\DBG:0.2) node{$g$};
  \draw (M) +(-90:0.2) node{$m$};
  \draw (N) +(-90:0.2) node{$n$};
  \draw (O) +(-45:0.2) node{$o$};
  \draw (P) +(-75:0.2) node{$p$};
 \end{tikzpicture}
\end{document}