Parts (node) with the same height Tikz

Question

How do I keep the two parties with the same height of 53mm?

\documentclass[a4paper,10pt]{book}
\usepackage{tikz}
\usetikzlibrary{positioning,shapes}
\begin{document}
%Tikz styles
\tikzset{>=latex,inner sep=0pt,
  cx1/.style={rectangle,draw,rounded corners=1cm,orange,text centered},
}

\begin{tikzpicture}[remember picture,overlay]
    \node[cx1,rectangle split,rectangle split parts=2,rectangle split parts,text width=5.3cm,text height=5.3cm] at (13.35,3.25) {aula\nodepart{second} $09$};
\end{tikzpicture}
\end{document}

I want it part1=53mm,part2=53mm.

Answer 1

You can use a \rule with a width of 0pt for this:

\node[cx1,rectangle split,rectangle split parts=2,text width=5.3cm] at (13.35,3.25) {\rule[-2.65cm]{0pt}{5.3cm}aula\nodepart{second}\rule[-2.65cm]{0pt}{5.3cm} $09$};