Elements I: Proposition 3
- Ryan Hirst
Euclid, The Elements, Book I Proposition III: To cut a line by a given length not on the same line.
The equilateral triangle can be constructed as a Regular Polyon on AC, or in the manner of Proposition I. In Geogebra, given segments AB = a > CD = b, Proposition 3 can be carried out in a single command: Segment[A, Intersect[Circle[A, b], a]]