21x29.7 = A4 = For golden section
This question has been occupying My mind for some time. The origin should be sought from the supporters of the Pythagorean theory (Pythagoreans), they defined it as a harmonic mathematical congruence. This cut's adherence gives a precise understanding of the size of the planned work and the arrangement of forms in it. In other words, the golden ratio means the derivative proportions of the square and circle shapes, which in the Pythagorean sense are complete geometric shapes.