抄録
The cathedral of Milan was begun in 1386. Stornaloco proposed that the section (96 braccia wide) be designed within an equilateral triangle, and the height of the equilateral triangle be 84 braccia. This projected triangle is "ideal equilateral". It shows the integration of the irrational proportion (4 : 2<√3 : 3) and rational proportion (8 : 7 : 6), and also the "Roriczerian method of equilateral triangle".
