\begin{definition}[Definition:Imperial/Area/Square Foot]
The '''square foot''' is an imperial unit of area.
One '''square foot''' is equal to a square of side $1$ foot in length.
{{begin-eqn}}
{{eqn | o = 
      | r = 1
      | c = '''square foot'''
}}
{{eqn | r = 144 = 12^2
      | c = square inches
}}
{{end-eqn}}
\end{definition}