Divide the line segment into two parts. The ratio of the length of the shorter part to the length of the longer part is equal to the ratio of the length of the longer part to the whole length. The ratio is an irrational number (5- 1)/2, and the approximation of the first three digits is 0.6 18. Because the shape designed according to this ratio is very beautiful, it is called the golden ratio.

The characteristics of the golden ratio:

The golden ratio is a mathematical proportional relationship. The golden ratio is strictly proportional, artistic and harmonious, and contains rich aesthetic value. Generally, it is 0.6 18 in application, just as pi is 3. 14 in application.

The aspect ratio of a golden rectangle is the golden ratio. In other words, the long side of a rectangle is 1.6 18 times of the short side. The golden ratio and the golden rectangle can bring aesthetic feeling to the picture, which is pleasant. It can be found in many artistic and natural works. The Pasa Shennong Temple in Athens, Greece is a good example. Leonardo da Vinci's Vitruvian people fit the golden rectangle, and Mona Lisa's face also fits the golden rectangle. The Last Supper also applied this proportional layout.