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Find the radius from the circumference

Grade 7 math · Fieldbook Learning

Name ______________________ Date __________

Work backwards: undo the formula to find the radius.

  1. A circle has a circumference of 357.96 cm. Use π = 3.14. What is its radius, in cm?
  2. A circle has a circumference of 94.2 cm. Use π = 3.14. What is its radius, in cm?
  3. A circle has a circumference of 131.88 cm. Use π = 3.14. What is its radius, in cm?
  4. A circle has a circumference of 37.68 cm. Use π = 3.14. What is its radius, in cm?
  5. A circle has a circumference of 119.32 cm. Use π = 3.14. What is its radius, in cm?
  6. A circle has a circumference of 502.4 cm. Use π = 3.14. What is its radius, in cm?
  7. A circle has a circumference of 414.48 cm. Use π = 3.14. What is its radius, in cm?
  8. A circle has a circumference of 376.8 cm. Use π = 3.14. What is its radius, in cm?
  9. A circle has a circumference of 320.28 cm. Use π = 3.14. What is its radius, in cm?
  10. A circle has a circumference of 427.04 cm. Use π = 3.14. What is its radius, in cm?
  11. A circle has a circumference of 364.24 cm. Use π = 3.14. What is its radius, in cm?
  12. A circle has a circumference of 477.28 cm. Use π = 3.14. What is its radius, in cm?
  13. A circle has a circumference of 822.68 cm. Use π = 3.14. What is its radius, in cm?
  14. A circle has a circumference of 527.52 cm. Use π = 3.14. What is its radius, in cm?
  15. A circle has a circumference of 640.56 cm. Use π = 3.14. What is its radius, in cm?
  16. A circle has a circumference of 395.64 cm. Use π = 3.14. What is its radius, in cm?
  17. A circle has a circumference of 307.72 cm. Use π = 3.14. What is its radius, in cm?
  18. A circle has a circumference of 847.8 cm. Use π = 3.14. What is its radius, in cm?
  19. A circle has a circumference of 703.36 cm. Use π = 3.14. What is its radius, in cm?
  20. A circle has a circumference of 1086.44 cm. Use π = 3.14. What is its radius, in cm?
More free practice: fieldbooklearning.com/ca/practice/grade-7/find-the-radius-from-the-circumference/

Play it as a quiz game

20 of these questions as multiple choice, with near-miss wrong answers, ready for Kahoot or Blooket.

  1. Download the game's own question template: in Kahoot, Add question → Import spreadsheet; in Blooket, Create a set → Spreadsheet import.
  2. Click the matching button below, then click the first empty question row of the template and paste.
  3. Save the template (Kahoot needs .xlsx, Blooket .csv) and upload it.
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Answer key: Find the radius from the circumference

  1. 57
  2. 15
  3. 21
  4. 6
  5. 19
  6. 80
  7. 66
  8. 60
  9. 51
  10. 68
  11. 58
  12. 76
  13. 131
  14. 84
  15. 102
  16. 63
  17. 49
  18. 135
  19. 112
  20. 173