7.- Star of David : The way of surrounding a circle by other circles, as it has been seen at the beginning, makes it possible to draw the Star of David...In order to get this it is enough to join suitably the centres of the 6 circles of the first orbit.
– A GEOMETRICAL LINK BETWEEN THE CIRCLE AND SEXAGESIMAL SYSTEM, by Jaime Vladimir TORRES-HEREDIA JULCA, Concept-global.net
There are practical geometrical theories as well. For example, if you wrap a rubber band around 7 soda cans (or any other convenient circular objects). You get a perfect hexagon with the 7th can in the middle. It is the only stable configuration of wrapping more than 3 circular objects. Four, 5, and 6 objects will slip from one configuration to another. Ancients wrapping tent poles, small logs for firewood, or other circular objects might have come upon this number and attach a mystical significance to it.
– What Is the Origin of the 7-Day Week, Calendars through the Ages,