Maths puzzle

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Across
  1. 2. The angle formed by the line of sight with the horizontal level when the point being viewed above the horizontal level.
  2. 5. The distance of a point from x axis.
  3. 6. A factor that means the ratio of the sides of the triangles to be constructed with the corresponding sides pf the given triangle.
  4. 9. A line that intersects a circle at only one point.
Down
  1. 1. The distance of a point from y axis.
  2. 3. The line drawn from the eyes of an observer to the point in the object viewed by the observer.
  3. 4. The study and relationship between sides and angles of a triangle.
  4. 7. The list of numbers in which each term is obtained by adding a fix number to the preceding term accept the first term.
  5. 8. A latin word meaning "piece cut off".