mathematician word puzzle

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Across
  1. 2. a straight line joining the centre of a circle or sphere to any point on the circumference or surface
  2. 4. the result of adding two or more numbers
  3. 6. mathematical statement that shows that two expressions are equal
  4. 7. number or quantity
  5. 13. proportion or rate per hundred parts
  6. 16. a quadrilateral whose opposite sides are parallel and equal in length pentagon
  7. 18. a quarter of the circumference of a circle
  8. 20. A ratio comparing a number to 100
Down
  1. 1. an integer exactly divisible by each denominator of a group of fractions: , , and have a common denominator of 12
  2. 3. a straight line connecting the centre of a geometric figure, esp a circle or sphere, with two points on the perimeter or surface
  3. 5. a number expressible as a limit of rational numbers
  4. 8. a section of a curve, graph, or geometric figure
  5. 9. numerical or constant factor
  6. 10. The number that indicates how many times the base is used as a factor
  7. 11. the boundary of a specific area or geometric figure, esp of a circle
  8. 12. a number or quantity that is a factor of each member of a group of numbers or quantities
  9. 14. a quotient of two numbers or quantities
  10. 15. An angle whose measure is greater than 0 and less than 90 degrees
  11. 17. measure of a region's size on a surface
  12. 19. one of two or three reference lines used in coordinate geometry to locate a point in a plane or in space