Geometry

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Across
  1. 3. infinite line
  2. 4. ||
  3. 6. line that start from point A
  4. 8. formed two rays
  5. 9. '⌒'
  6. 10. 3.141592654...
Down
  1. 1. Δ
  2. 2. °
  3. 5. 90°
  4. 7. C