Golden measurements

To create a Golden section, take a square (1 by 1). Using the mid point of the base as centre, draw an arc (radius) from one of the top corners down to meet the baseline. The bottom corner of the square now sits on the 'golden section' point. And, significantly, the two key controlling numbers of the golden section have also been created: 'Phi' (large) and 'Phi' (small)