\documentclass[12pt, varwidth, border=5mm]{standalone}
\usepackage{tikz}
\usepackage{amsmath}
% Underlining package
\usepackage{ulem}
\usetikzlibrary{calc}
\usetikzlibrary{angles,quotes}
% \usepackage[a4paper, portrait, margin=1cm]{geometry}

\begin{document}
\section*{ }
    \begin{minipage}{0.55\textwidth}
  \begin{tikzpicture}[scale=1.0, baseline=(current bounding box.north)]
    \begin{scope}[rotate=-20]
        % Draw square
        \draw (0,0) coordinate (W) --
              ++(2.209,0) coordinate (X) --
              ++(0,2.209) coordinate (Y) --
              ++(-2.209,0) coordinate (Z) -- cycle;

        % Right angle markers
        \foreach \p/\q/\r in {Z/W/X,W/X/Y,X/Y/Z,Y/Z/W} {
            \pic [draw, -, angle radius=0.2cm] {right angle=\p--\q--\r};
        }

        % Vertex LABELS
        % Labels relative to shape geometry
        \node at ($(W)+(-0.2,-0.2)$) {W};
        \node at ($(X)+(0.2,-0.2)$) {X};
        \node at ($(Y)+(0.2,0.2)$) {Y};
        \node at ($(Z)+(-0.2,0.2)$) {Z};

        % Tick marks across horizontal sides
        \draw[thin, gray]
            ($(W)!0.5!(X) + (0,-0.10)$) --
            ($(W)!0.5!(X) + (0,0.10)$);

        \draw[thin, gray]
            ($(Z)!0.5!(Y) + (0,-0.10)$) --
            ($(Z)!0.5!(Y) + (0,0.10)$);

        % Tick marks across vertical sides
        \draw[thin, gray]
            ($(X)!0.5!(Y) + (-0.10,0)$) --
            ($(X)!0.5!(Y) + (0.10,0)$);

        \draw[thin, gray]
            ($(W)!0.5!(Z) + (-0.10,0)$) --
            ($(W)!0.5!(Z) + (0.10,0)$);

        % dotted/dashed arrows shifted away from edges
        % % Vertical side (B-C), shifted right
        \draw[<->, gray]
            ($(X) + (0.50cm,0)$) -- ($(Y) + (0.50cm,0)$)
            node[black, midway, fill=white, xshift=2mm, inner sep=3pt] {3\,cm};

    \end{scope}
\end{tikzpicture}
\end{minipage}%
\hfill
\begin{minipage}{.4\textwidth}
  \begin{align*}
  \text{Area} &= l^2 \\
  \text{Area} &= \dotuline{~~~~~~~} \,\text{cm} \times \dotuline{~~~~~~~} \,\text{cm} \\
  \text{Area} &= \dotuline{~~~~~~~} \,\text{cm}^2
  \end{align*}
\end{minipage}

\end{document}