Geometry Puzzle

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Across
  1. 2. a precise location or place on a plane usually represented by a dot
  2. 6. the middle of the line segment
  3. 8. two coplanar lines that do not intersect but go on forever
  4. 9. is the length of a line segment from its center to its perimeter
  5. 10. line that meets at 90
  6. 12. two end points and all the points in between them
  7. 13. four parts of a coordinate plane
  8. 16. these two angles adds up to 90
  9. 17. these two angles adds up to 180
  10. 19. any straight line segment that passes through the center of the circle
  11. 20. the distance around a two-dimensional shape
Down
  1. 1. the distance around the circle, it's the circle's perimeter
  2. 3. an angle greater than 90 but less than 180
  3. 4. points that lie on the same plane
  4. 5. geometric elements of equal measure
  5. 7. points that are on the same line
  6. 11. two non adjacent angles formed by two intersecting lines
  7. 14. a line with a single endpoint and goes on forever in one direction
  8. 15. 0-90 degrees
  9. 18. the set of all points collinear to 2 point