When dividing, the length is about 0.6 18, which is called golden section. This demarcation point is called the golden section.

Divide a line segment into two parts so that the ratio of one part to the total length is equal to the ratio of the other part to this part. Its ratio is an irrational number, expressed in fractions as √5- 1/2, and the approximate value of the first three digits is 0.6 18. Because the shape designed according to this ratio is very beautiful, it is called golden section, also called Chinese-foreign ratio. This is a very interesting number, which is expressed by 0.6 18. Through simple calculation, we can find that:

1/0.6 18= 1.6 18

( 1-0.6 18)/0.6 18=0.6 18