\begin{definition}[Definition:Euclid's Definitions - Book III/10 - Sector of Circle]
{{EuclidSaid}}
:''A '''sector of a circle''' is the figure which, when an angle is constructed at the center of the circle, is contained by the straight lines containing the angle and the circumference cut off by them.''
{{EuclidDefRef|III|10|Sector of Circle}}
\end{definition}