Outline
circles, ovals, ellipses and architecture
We know the circle as an elementary figure that's often used in architecture, sometimes as a cosmic symbol.
We know the ellips as a conic and since Kepler also as the orbit planets follow around the sun.
Compared with circle and ellipse the oval is the ugly duc. It cannot be described by one equation, we say that baroc architects used ovals as an approximation of an ellips, in books and touristic guides ovals and ellipses are mixed etc. However the history of the oval reads as a fascinating and ancient story. Based on a lot of articles, supplemented by GeoGebra applets I will try to guide you through this story, thanks to some support of some ex colleagues from school.
