Origami Axioms and Constructible Numbers by Origami

Atakan Özcan and Pınar Ecem Akyıldırım, Dokuz Eylül University.
Date: 4th of December, 2025, Thursday, Time: 15.00 – 16.00.
Place: Dokuz Eylül Univ., Tınaztepe Campus, Faculty of Science, Department of Mathematics, Classroom B255.

Abstract: We will firstly mention straightedge-compass constructions and five axioms for them. By straightedge and compass constructions, we will talk about, drawing lines and circles, constructions of a perpendicular to a given line through a given point, drawing a parallel line to a given line passing through a given point and bisecting an angle. Then we will see basic properties of origami and the Huzita-Hatori seven postulates for origami. Another set of axioms for origami is obtained by just adding another axiom to the five axioms of straightedge-compass constructions. We will show the equivalence between these two sets of axioms for origami. Trisection of an angle is known to be impossible using straightedge and compass constructions, but we will see that it is possible using origami constructions.