\begin{definition}[Definition:Euclid's Definitions - Book VI/3 - Extreme and Mean Ratio]
{{EuclidSaid}}
:''A straight line is said to have been '''cut in extreme and mean ratio''' when, as the whole line is to the greater segment, so is the greater to the less.''
{{EuclidDefRef|VI|3|Extreme and Mean Ratio}}
\end{definition}