Editing Shape (section)

===Congruence and similarity===
{{Main|Congruence (geometry)|Similarity (geometry)}}
Objects that can be transformed into each other by rigid transformations and mirroring (but not scaling) are [[Congruence (geometry)|congruent]]. An object is therefore congruent to its [[mirror image]] (even if it is not symmetric), but not to a scaled version. Two congruent objects always have either the same shape or mirror image shapes, and have the same size.

Objects that have the same shape or mirror image shapes are called [[geometrically similar]], whether or not they have the same size. Thus, objects that can be transformed into each other by rigid transformations, mirroring, and uniform scaling are similar. Similarity is preserved when one of the objects is uniformly scaled, while congruence is not. Thus, congruent objects are always geometrically similar, but similar objects may not be congruent, as they may have different size.