What is the golden section?

It is a question put forward by Euclid in the Principle of Geometry: "Divide a line segment into two segments so that the product of the whole segment and one segment is equal to the square of the other segment." Dividing line segments according to the above requirements is called "golden section" by the famous Italian painter Leonardo da Vinci, also known as "Chinese-foreign ratio".

It is also expressed as: "divide the known line segment into two segments, so that the long segment is the median ratio of the whole line segment to the short segment."

Given the length of line segment AB as a, divide it into two segments with point C, one segment is X and the other segment is a-x, and x=0.6 18a can be obtained, where point C is called the optimal segmentation point of line segment AB, also called the golden section point.