dynamic geometry

A recent paper by Bizony (2017) discussed the interesting golden ratio properties of a Kepler triangle, defined as a right-angled triangle with its sides in geometric progression in the ratio 1 : √φ : φ, where φ =  (1 + √5)/2

Haga’s Origamic activities require students to explore simple, geometric properties found when we fold paper in prescribed ways. The aim of these activities is to give students easy-to-explore paperfolding puzzles so that they can experience a micro-version of the three stages of mathematical research: exploration, conjecture and proof. In this article, we take up another ‘origamics’ exploration by Dr. Kazuo Haga from the chapter 'Intrasquares and Extrasquares' of his book.