This question already has an answer here:

My shape is composed of 7 polygons which are supposed to be adjacent (ie sharing sharing same nodes). Would like to join the polygons by their nodes and make sure there is no space in between two polygons. But the 7 polygons maintained separately. Is there a way to do that?

marked as duplicate by Hornbydd, BERA, ArMoraer, nmtoken, user30184 May 16 '18 at 10:58

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

Browse other questions tagged or ask your own question.