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Number of diagonals of a polygon

Year 9 maths · Fieldbook Learning

Name ______________________ Date __________

From each corner draw lines to every corner except itself and its two neighbours. Each diagonal is counted twice.

  1. How many diagonals does a polygon with 34 sides have?
  2. How many diagonals does a polygon with 56 sides have?
  3. How many diagonals does a polygon with 43 sides have?
  4. How many diagonals does a polygon with 35 sides have?
  5. How many diagonals does a polygon with 59 sides have?
  6. How many diagonals does a polygon with 10 sides have?
  7. How many diagonals does a polygon with 13 sides have?
  8. How many diagonals does a polygon with 62 sides have?
  9. How many diagonals does a polygon with 88 sides have?
  10. How many diagonals does a polygon with 74 sides have?
  11. How many diagonals does a polygon with 70 sides have?
  12. How many diagonals does a polygon with 78 sides have?
  13. How many diagonals does a polygon with 73 sides have?
  14. How many diagonals does a polygon with 49 sides have?
  15. How many diagonals does a polygon with 33 sides have?
  16. How many diagonals does a polygon with 40 sides have?
  17. How many diagonals does a polygon with 52 sides have?
  18. How many diagonals does a polygon with 82 sides have?
  19. How many diagonals does a polygon with 163 sides have?
  20. How many diagonals does a polygon with 183 sides have?
More free practice: fieldbooklearning.com/uk/practice/year-9/number-of-diagonals-of-a-polygon/

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Answer key: Number of diagonals of a polygon

  1. 527
  2. 1484
  3. 860
  4. 560
  5. 1652
  6. 35
  7. 65
  8. 1829
  9. 3740
  10. 2627
  11. 2345
  12. 2925
  13. 2555
  14. 1127
  15. 495
  16. 740
  17. 1274
  18. 3239
  19. 13040
  20. 16470