Geometry Puzzle

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Across
  1. 4. Lines that are not coplanar
  2. 5. A triangle with three acute angles
  3. 6. Two vectors that have the same magnitude and are goin the same direction
  4. 7. The angle formed by a horizontal line and a line of sight to a point below
  5. 9. A ratio of two sides of a right triangle
  6. 12. A segment that is between two points and is going a certain direction
  7. 14. A pair of adjacent angles whose no common side are opposite rays
  8. 15. A quadrilateral with exactly two pairs of congruent consecutive sides
  9. 16. A ray that divides an angle in to two congruent angles
  10. 18. A chart that uses boxes and arrows to show the structure of the proof
  11. 19. A quantity that has both magnitude and direction
  12. 20. A point that divides a segment into two congruent segments
Down
  1. 1. The point of concurrency of the three angle bisectors of a triangle
  2. 2. A proof in which the statement is assumed to be false and a contradiction is shown
  3. 3. A repeating pattern of plane figures that completely covers a plane with no gaps or overlaps
  4. 8. A transformation that does not change the size or shape of the figure
  5. 10. Starting point of a vector
  6. 11. Ten- sided polygon
  7. 13. Abbreviation for "corresponding parts of congruent triangles are congruent"
  8. 17. A polygon in which no diagonal contains points on the exterior of the polygon