The Basics in Geometry

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Across
  1. 2. On the same line
  2. 4. Extends in both directions endlessly
  3. 6. Named with a single capital letter
  4. 7. Not on the same line
  5. 8. A piece of a line
Down
  1. 1. On the same plane
  2. 3. Extends in one directions forever
  3. 5. The father of Geometry
  4. 6. 3D figure