;

Analogy application: (2) Divide a regular triangle into four small regular triangles;

;

(3) Divide a regular triangle into six small regular triangles:

(4) Divide a regular triangle into 9 10 and 1 1 small regular triangles:

;

(5) dividing a regular triangle into n(n≥9) small regular triangles: dividing a regular triangle into 9, 1 0 and 10 small regular triangles by "basic division method1"or "basic division method 2" or their combination. Thus a regular triangle can be divided into 12, 13 and 14 small regular triangles, and so on, a regular triangle can be divided into n (n≥9) small regular triangles.