42 people dancing in a triangle, how to line up, the most dazzling national wind square dance

42 people in a triangle square dance, each side of the number of people the same or difference of 1 person, the number of people in each row is also the same or difference of 1 person, how to row? Here is one way to line up:

1. Divide into 14 groups of 3 people each.

2. Each group pulls hands in a circle and stands still.

3. Group 1 turns counterclockwise.

4. Group 2 does not turn around, but moves one position to the left.

5. Group 3 does not turn in a circle and moves only two positions to the left.

6. Group 4 people do not spin and move only three positions to the left.

7. Group 5 people do not spin and move only four positions to the left.

8. Group 6 people do not spin and move only five positions to the left.

9. Group 7 people do not spin and move only six positions to the left.

10. The person in group 8 does not spin and moves only seven positions to the left.

11. Group 9 does not spin and moves only eight positions to the left.

12. Group 10 does not spin and moves nine positions to the left only.

13. Group 11 does not spin and moves ten positions to the left only.

14. Group 12 does not spin and moves eleven positions to the left only.

15. The 13th group does not spin and moves only twelve positions to the left.

16. The 14th group does not spin and moves only thirteen positions to the left.

When lined up in this way, the number of people in each row is equal or different by one, and the number of people on each side is equal or different by one.