In a WordPress blog post of mine I used the following LaTeX code:
$\setlength{\unitlength}{1cm}
\begin{picture}(8,6)\thicklines
\put(1,1){\line(3,4){3}}
\put(4,5){\line(3,-4){3}}
\put(1,1){\line(1,0){6}}
\put(2.3,3.2){\textit{b}}
\put(5.7,3.1){\textit{a}}
\put(3.8,0.5){\textit{c}}
\put(4,2.7){\textit{S}}
\put(0.6,0.5){\textit{A}}
\put(7.1,0.5){\textit{B}}
\put(3.8,5.3){\textit{C}}
\end{picture}$
to draw a triangle. I tried to do the same in this answer but it didn't parse.
Question: Is this feature not allowed/supported?
Added: From the Willie Wong's comment to J. M.'s answer it seems this is due to the existing design of the system. Is that so?
$latex code$
. $\endgroup$