Umbo : Tofauti kati ya masahihisho

[[File:Congruent non-congruent triangles.svg|thumb|370px|An example of the different definitions of shape. The two triangles on the left are congruent, while the third is Similarity (geometry)| Sawa na wao. Pembetatu ya mwisho sio sawa wala haihusiani na yoyote ya wengine, lakini ni homeomorphic.]]

Muundo ni fomu ya kitu au mipaka yake ya nje, muhtasari, au uso wa nje, kinyume na mali nyingine kama [[rangi]], texture, au muundo wa nyenzo.