chapter 6 crossword except i have no idea

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Across
  1. 5. ray addition?
  2. 8. 60-60-60
  3. 10. strict quadrangle
  4. 12. in between horizontal and vertical
  5. 13. two parallels
  6. 15. some parallels
  7. 16. altitude center
  8. 17. middle of data
  9. 18. equilateral quadrangle
Down
  1. 1. circumcircle center
  2. 2. another center
  3. 3. the same measure
  4. 4. combining things
  5. 6. adjacent pairs
  6. 7. the same distance
  7. 9. incircle center
  8. 11. height thing
  9. 14. equiangular quadrangle