The cinquefoil or pentagram geometric incorporates the Golden proportion, as it is based on the diagonal of the half square, which is also, of course, a double square. The diagonal of the double square is equal to the square root of 5, approximately 2.236. Half of that is 1.118, which is 0.5 from the golden, either way :-) # Widely used in medieval architecture and elsewhere... # The small diagrams at the right are the sequence of arcs to begin... Circle bisected, and quartered, a second arc centered on the mid point of the right segment, radius to the upper extreme of the top segment, etc. # Walnut ink and watercolor on Czech heavy handmade paper from @rucni_papirna_velke_losiny mills # #geometry #sacred #proportion #root5 #goldensection #sectioaurea #hermeticengrossing #hermes # @hermeticlibrary # See FB "Society for the Golden Section" and "Mindful Play and Tools for Resilience" (at Galena Design Foundation) https://www.instagram.com/p/BpnF55ADhsC/?utm_source=ig_tumblr_share&igshid=1qisk3jv4chsw
