Mathematics in table tennis

1234567
Across
  1. 4. The relation between two adjacent sides of table tennis table.
  2. 6. The deduction method of table tennis.
  3. 7. Table tennis table two non-adjacent side of the relationship.
Down
  1. 1. The shape of the table tennis table.
  2. 2. How do the judges determine the mistakes in the table tennis match？
  3. 3. The four angle of the table tennis table.
  4. 5. The scoring method of table tennis.