\begin{definition}[Definition:Congruence (Geometry)]
In the field of Euclidean geometry, two geometric figures are '''congruent''' if they are, informally speaking, both "the same size and shape".
That is, one figure can be overlaid on the other figure with a series of rotations, translations, and reflections.
Specifically:
:all corresponding angles of the '''congruent''' figures must have the same measurement
:all corresponding sides of the '''congruent''' figures must be be the same length.
\end{definition}