In my practice of construction is often the task of removing the right angle on the Foundation. This plays an important role in the further construction of walls and roof installation.
This problem can be solved in several ways. For example, with the help of level. I specifically shot a training video of this process, which can be viewed on my YouTube channel
I think that everything is very clear there. There is also a video on other topics of construction. I hope it will be useful and interesting for someone. Waiting for a visit with comments and questions.