\documentclass{minimal}
\usepackage{amsmath}
\usepackage{tikz}
\begin{document}

\tikz \fill[green] rectangle (0.5,0.5); Something
    about something.

    \[
  1+1
      \]

\begin{align}
    2+2=4
\end{align}

\begin{itemize}
\item item is indented twice
      and the next line is indented to match
\end{itemize}

\begin{equation}
   \left(
     f(x) = 3
  \right)
  \left.
      f(x) = 3
\right.
\end{equation}

{
    asdasd
  }

  \begin{tikzpicture}
     \draw [solid] let \p{I} = (0,0) in (1,1) -|
        (\x{I}-1cm,-1cm) node [yshift=-.25cm] {(i)};
     % Just some comment
     \end{tikzpicture}

     \begin{tikzpicture}
% (i) center contact head
\draw [solid] let \p{I} = (centerContactHead) in (centerContactHead) -|
  (\x{I}-.75cm,-2.5)
  node [yshift=-.25cm] {(i)};

% (ii) outer conductor of the contact head
  \coordinate (outerContactHead) at (.8,-1.7);
  \draw [solid] let \p{O} = (outerContactHead)
    in (outerContactHead) -- (\x{O},-2.5)
      node [yshift=-.25cm] {(ii)};
     \end{tikzpicture}

  \end{document}