Chapter 4 of the book:
“From Riemann Hypothesis to CPS Geometry and Back  Volume 1 (https://www.amazon.com/dp/B08JG1DLCV) ”, Canadian Intellectual Property Office Registration Number: 1173734 (http://www.ic.gc.ca/app/opic-cipo/cpyrghts/srch.do?lang=eng&page=1&searchCriteriaBean.textField1=1173734&searchCriteriaBean.column1=COP_REG_NUM&submitButton=Search&searchCriteriaBean.andOr1=and&searchCriteriaBean.textField2=&searchCriteriaBean.column2=TITLE&searchCriteriaBean.andOr2=and&searchCriteriaBean.textField3=&searchCriteriaBean.column3=TITLE&searchCriteriaBean.type=&searchCriteriaBean.dateStart=&searchCriteriaBean.dateEnd=&searchCriteriaBean.sortSpec=&searchCriteriaBean.maxDocCount=200&searchCriteriaBean.docsPerPage=10) , Ottawa, ISBN 9798685065292, 2020.
On Google Books:
https://books.google.ca/books/about?id=jFQjEQAAQBAJ&redir_esc=y
On Google Play: https://play.google.com/store/books/details?id=jFQjEQAAQBAJ

The provided text introduces the Euclidean Algorithm, a method for finding the greatest common divisor (GCD) of two integers. The algorithm is presented both conceptually, as finding the smallest common unit of measurement, and procedurally, using a series of divisions and remainders. The text then explores the algorithm's application to line segments, highlighting the implicit assumption of a common unit of length. It concludes by acknowledging that the algorithm relies on the existence of a common unit (like the number 1 for integers) and may not be directly applicable to all pairs of line segments.