1, each number is equal to the sum of the two numbers above it.

2. The numbers in each row are symmetrical left and right, and gradually increase from 1.

3. The number in line n is n+ 1.

4. The sum of the numbers in the nth row is 2 (n- 1) (2 to the power of (n- 1)).

5. The coefficients in the (a+b) n expansion correspond to each item in the (n+ 1) line of Yang Hui Triangle in turn.

6. The number m in the nth row is equal to the number n-m, that is, C(n, m)=C(n, n-m), which is the property of the combination number.

Introduction:

Yang Hui triangle is a geometric arrangement of binomial coefficients in triangle. The book "Detailed Explanation of Nine Chapters' Algorithms" written by Yang Hui, a mathematician of the Southern Song Dynasty in China, appeared in 126 1. In Europe, Pascal (1623- 1662) was published in 1654.

Symmetry: The numbers in Yang Hui triangle are symmetrical left and right, and the symmetry axis is the "height" of the bottom of Yang Hui triangle.

Structural features: All numbers of Yang Hui triangle except 1 on the hypotenuse are equal to the sum of two numbers on its shoulder.