Welcome to QGIS Tutorial. In this article, I will show you how to create a polygon from points in QGIS. So for this example, I have a Tenement_block table that has a few columns such as Nodes_X, Nodes_Y which are the coordinates of the points, BlockID which differentiate each polygon, and also Node which is the point number.
This is the points in the QGIS canvas
First, we are going to create polylines from the points. Find the tool Points to Path from the Toolbox. You can use the search box to find the tool we need.
Select the input point layer (Tenement_block layer). And then, select the Node in the Order field. BlockID is used as the group field. By doing this, we will tell QGIS to create polylines and group them using BlockID. Also, the lines will be created based on the order field (Node)
This is the result
Now, we will create polygons from this path layer we just created. Go to Vector | Lines to Polygons.
Done. Now we have successfully created polygons from points. This is useful when we have to build or create many polygons from points. Rather than doing manually, you can try this method. Below is the attribute table of the polygons layer.