number series

12345678910111213141516171819
Across
  1. 3. - three
  2. 4. - being one sided
  3. 6. - animal written about in fables
  4. 7. - one, single
  5. 9. - tacking place every two hundred years
  6. 11. - to make one
  7. 13. - two , twice
  8. 14. - being three sided
  9. 16. - number named with nine zeros after it, 1000
  10. 17. -to cut or divide something into two parts
  11. 19. - a two winged animal
Down
  1. 1. - appears once a year
  2. 2. - a one wheeled vehicle
  3. 3. - number named by a unit with twelve zeros, 1,000,000,000,000
  4. 5. - lasting for two years
  5. 8. -tacking place once a year
  6. 10. - of or pertaining to three languages
  7. 11. - a one-leg support
  8. 12. - of or pertaining to one language
  9. 15. - a shape with three sides
  10. 18. -a three legged support
  11. 19. - a two footed animal