What is it?
Sacred geometry is a belief that inside specific forms and shapes it is possible to access spiritual levels of consciousness and elevate the spirit. Sacred geometry was used as a tool to help men and women experienced the divine element through the use of specific shape and forms that could be replicated in architectural elements.
where did it originate?
There was not a single place that used Sacred geometry, however, it is possible to find examples of such uses already in the Egypt culture, as well as the Celtic culture and even cultures from Asia and America. It is pretty common in the history of man to use such tools in different ways. Some elements of Gothic Cathedral uses sacred geometry.
How?
Mostly the use of sacred geometry was in rituals. By walking through a labyrinth, for example, just like in Chartres, it was believed that the spirit could elevate from the flesh. Or also in the way some buildings were constructed, just by enter in the buildings, some claims to feel different from before, as the construction itself is a tool towards illumination.
Where was it used?
The use was different, but the most known use of sacred geometry is in building constructions and architecture, mostly sacred like temple and church. It is also possible to find examples of sacred geometry in some theoretical studies - Pitagora used to believe in sacred geometry, just to name one thinker of the past.