정삼각형이 둘이면 꼭지점은 6, 셋이면 9, 넷이면 12 등으로 꼭지점의 수가 늘어납니다.
If there are two equilateral triangles, the number of angular point is 6, and if there are three equilateral triangles, the number of angular point increases to 9, and 12 for four equilateral triangles.