You can see there is some blotting at the beginning of lines – look at the red lines top right – as well as a little unevenness in line thickness.
It was carried out to explore the relationship between stars based on ten-point geometry and there must have been construction lines before this was drawn, perhaps just pencilled in as these were all drawn manually rather than with a computer.
Sometimes this happens, as can be seen on the 120° angle on the left but, on the other two angles this has not been accomplished.
Considerable patience was needed in creating these drawings.
It is placed here to show something of the concentration that goes into study of this character of geometry as well as the accuracy I tried to maintain in drafting.
Nowadays, drawing with computer programmes, there are still inaccuracies, but they are easier to deal with than when drawing with ink on paper.