This tutorial showed how to draw regular shapes (Triangle, Square, Rectangle) with proper dimensions in QGIS. This QGIS tutorial shows the total process of drawing a site with a fixed dimension in QGIS. In the 1st part, I showed how to find the proper CRS for the project and fixing the CRS for measurement.
In the 2nd part of this tutorial, I showed how to draw any shape in QGIS with a fixed dimension. TO do this here I used the Advanced digitizing toolbar.