The goal is to build this sangaku 3D Hexlet called Soddy (see wikipedia: [url]https://en.wikipedia.org/wiki/Soddy's_hexlet[/url]) consisting of internally tangent spheres in a large sphere. Each sphere inside is tangent to at least 4 other spheres, see detailed explanation at: [url]http://mathmj.fr/geogebra/hexlet.pdf[/url] ( Written in fFrench, I need help to translate it in English : jacques.marot@outlook.fr)
