Random scale of square makes a rectangle

Question

Why does this code generates a rectangle, not a square?

\documentclass{standalone}
\usepackage{tikz}

\begin{document}
\begin{tikzpicture}
    \draw[scale=rnd] (0,0) rectangle (1,1);
\end{tikzpicture}
\end{document}

Answer 1

Every coordinate of (1,1) is multiplied with the value of scale. So you have two values x and y which will be multiplied with rnd. And of course rnd isn't equal for x and y.

To use rnd as an option of scale you can do the following:

\documentclass[12pt]{article}
\usepackage{tikz}

\begin{document}
\begin{tikzpicture}
\pgfmathparse{rnd}
    \draw[scale=\pgfmathresult] (0,0) rectangle (1,1);
\end{tikzpicture}
\begin{tikzpicture}
    \draw[scale=1] (0,0) rectangle (1,1);
\end{tikzpicture}
\end{document}