I am a student majoring in aerobics in the Institute of Physical Education. The answers to your questions are as follows:

The venues for mixed doubles, three people and six people are all 10M× 10M.

If there is a competition table, the height of the competition table is 80- 140cm, the competition table is not less than 14M× 14M, and the sign belt is a black belt with a width of 5CM, which belongs to the venue.

I hope I can help you ~