\begin{definition}[Definition:Euclid's Definitions - Book VII/16 - Plane Number]
{{EuclidSaid}}
:''And, when two numbers having multiplied one another make some number, the number so produced is called '''plane''', and its '''sides''' are the numbers which have multiplied one another.''
{{EuclidDefRef|VII|16|Plane Number}}
\end{definition}