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Find a missing side from the perimeter

Grade 3 math · Fieldbook Learning

Name ______________________ Date __________

Use the perimeter and the side you know to find the other side. Write the number only.

  1. A rectangular tile has a perimeter of 18 m and is 7 m long. How wide is it? Write the number only.
  2. A rectangular poster has a perimeter of 28 m and is 7 m long. How wide is it? Write the number only.
  3. A rectangular rug has a perimeter of 12 cm and is 3 cm long. How wide is it? Write the number only.
  4. A rectangular banner has a perimeter of 24 m and is 5 m long. How wide is it? Write the number only.
  5. A rectangular mat has a perimeter of 18 m and is 4 m long. How wide is it? Write the number only.
  6. A rectangle has a perimeter of 16 cm and is 6 cm long. How wide is it? Write the number only.
  7. A rectangular banner has a perimeter of 34 m and is 8 m long. How wide is it? Write the number only.
  8. A rectangular card has a perimeter of 16 cm and is 2 cm long. How wide is it? Write the number only.
  9. A rectangular garden has a perimeter of 22 cm and is 7 cm long. How wide is it? Write the number only.
  10. A rectangular tile has a perimeter of 36 cm and is 6 cm long. How wide is it? Write the number only.
  11. A rectangular banner has a perimeter of 32 cm and is 7 cm long. How wide is it? Write the number only.
  12. A rectangular tile has a perimeter of 36 m and is 6 m long. How wide is it? Write the number only.
  13. A rectangular poster has a perimeter of 34 m and is 12 m long. How wide is it? Write the number only.
  14. A rectangular rug has a perimeter of 60 m and is 15 m long. How wide is it? Write the number only.
  15. A rectangle has a perimeter of 54 cm and is 13 cm long. How wide is it? Write the number only.
  16. A rectangular card has a perimeter of 40 cm and is 9 cm long. How wide is it? Write the number only.
  17. A rectangular card has a perimeter of 38 m and is 6 m long. How wide is it? Write the number only.
  18. A rectangular garden has a perimeter of 52 cm and is 9 cm long. How wide is it? Write the number only.
  19. A rectangular card has a perimeter of 68 cm and is 16 cm long. How wide is it? Write the number only.
  20. A rectangular poster has a perimeter of 52 m and is 14 m long. How wide is it? Write the number only.
More free practice: fieldbooklearning.com/practice/grade-3/find-a-missing-side-from-the-perimeter/

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.
Download CSV

Answer key: Find a missing side from the perimeter

  1. 2
  2. 7
  3. 3
  4. 7
  5. 5
  6. 2
  7. 9
  8. 6
  9. 4
  10. 12
  11. 9
  12. 12
  13. 5
  14. 15
  15. 14
  16. 11
  17. 13
  18. 17
  19. 18
  20. 12