Jo Niemeyer, A simple construction of the golden section,
Forum Geometricorum, 11 (2011) 53.


Full Text.   Three equal segments A_1B_1, A_2B_2, A_3B_3 are positioned in such a way that the endpoints B_2, B_3 are the midpoints of A_1B_1, A_2B_2 respectively, while the endpoints A_1, A_2, A_3 are on a line perpendicular to A_1B_1. In this arrangement, A_2 divides A_1A_3 in the golden ratio.

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