# Tikz modify part of polar coordinates

I wish to draw a deformed hexagon, defined by polar coordinates. I wish define a distance \aI and express the second polar coordinates using with this variable, but I get complying error.

! Package PGF Math Error: Unknown operator $' or$(' (in '($(0.482962913'). My MnWE (Minimal not-Working Example): \documentclass{memoir} \usepackage{xcolor} \usepackage{tikz} \usetikzlibrary{shapes.geometric,positioning,calc} \usepackage{calc} \begin{document} \begin{center} \newdimen\aI \aI=1cm \begin{tikzpicture}[rotate=0] \begin{scope}[yshift=0cm] \draw[yshift=0cm] (37.5:($ (0.482962913)*(\aI) $)) -- (90:($ (1.276316253*\aI) $)) -- (142.5:($ (0.482962913*\aI) $)) -- (232.5:($ (0.482962913*\aI) $)) -- (270:($ (1.276316253*\aI) $)) -- (307.5:($ (0.482962913*\aI) $)) -- cycle ; \end{scope} \end{tikzpicture} \end{center} \end{document}  Helps will be welcomed. ## 1 Answer You don't need these $ signs or the extra () either.

\begin{tikzpicture}[rotate=0]
\begin{scope}[yshift=0cm]
\draw[yshift=0cm] (37.5:0.482962913\aI) --
(90:1.276316253\aI)    -- (142.5:0.482962913\aI) --
(232.5:0.482962913\aI) -- (270:1.276316253\aI) --
(307.5:0.482962913\aI) -- cycle ;
\end{scope}
\end{tikzpicture}