Once fully appreciated this uncontainable mistery of the cosmic equilibrium, so marvellous Creation Module as to be claimed as Divine Proportion – Latin: sectio divina – (although trivially defined just as by line and segments), we can turn to discover probably the best geometric expression of its power.
Having drawn the Golden Rectangle, to build the so called Kepler triangle, nothing more but to use as the base the short side LA and
for the hypotenuse the long one AB, rotating it
toward the opposite side AC up to meet it in C.
Mirroring the AC side to the opposite side of the height CL, the CD side will define the full ‘magic’ triangle CAD, without revealing all its amazing props though.
That’s to say this wonderful triangle - whose sum of the two sides is in phi ratio with the base - worthy to be at all regarded as the “Great” (like the Pyramid where it came from) Golden (but why not also 'True'?), virtually holds in itself at least the 4 concentric circles with diameters ruled by progressive exponents of the Golden Ratio, as it defines them starting from the bigger circumscribed; to the immediately internal one, tangent to its sides; to the third, when tangent both to the triangle base and to the ‘main’ outer circle; then to the inner one, tangent to its base from the concentric position.