Create a free account now and get 3 full lessons, completely free. Get my 3 free lessons

Practise online insteadThe answer key prints on page 2.

Is the triangle acute, right or obtuse?

Grade 8 math · Fieldbook Learning

Name ______________________ Date __________

Compare the sum of the squares of the two shorter sides with the square of the longest side. Equal: right. Greater: acute. Less: obtuse.

  1. A triangle has sides of 6, 5 and 4. Is it acute, right or obtuse? Write acute, right or obtuse.
  2. A triangle has sides of 18, 6 and 21. Is it acute, right or obtuse? Write acute, right or obtuse.
  3. A triangle has sides of 19, 19 and 8. Is it acute, right or obtuse? Write acute, right or obtuse.
  4. A triangle has sides of 14, 19 and 23. Is it acute, right or obtuse? Write acute, right or obtuse.
  5. A triangle has sides of 12, 13 and 20. Is it acute, right or obtuse? Write acute, right or obtuse.
  6. A triangle has sides of 18, 25 and 21. Is it acute, right or obtuse? Write acute, right or obtuse.
  7. A triangle has sides of 18, 14 and 26. Is it acute, right or obtuse? Write acute, right or obtuse.
  8. A triangle has sides of 19, 13 and 31. Is it acute, right or obtuse? Write acute, right or obtuse.
  9. A triangle has sides of 8, 17 and 23. Is it acute, right or obtuse? Write acute, right or obtuse.
  10. A triangle has sides of 28, 5 and 30. Is it acute, right or obtuse? Write acute, right or obtuse.
  11. A triangle has sides of 11, 24 and 18. Is it acute, right or obtuse? Write acute, right or obtuse.
  12. A triangle has sides of 8, 20 and 19. Is it acute, right or obtuse? Write acute, right or obtuse.
  13. A triangle has sides of 10, 33 and 40. Is it acute, right or obtuse? Write acute, right or obtuse.
  14. A triangle has sides of 35, 32 and 29. Is it acute, right or obtuse? Write acute, right or obtuse.
  15. A triangle has sides of 36, 10 and 34. Is it acute, right or obtuse? Write acute, right or obtuse.
  16. A triangle has sides of 26, 25 and 40. Is it acute, right or obtuse? Write acute, right or obtuse.
  17. A triangle has sides of 48, 10 and 48. Is it acute, right or obtuse? Write acute, right or obtuse.
  18. A triangle has sides of 30, 50 and 53. Is it acute, right or obtuse? Write acute, right or obtuse.
  19. A triangle has sides of 31, 8 and 24. Is it acute, right or obtuse? Write acute, right or obtuse.
  20. A triangle has sides of 45, 11 and 36. Is it acute, right or obtuse? Write acute, right or obtuse.
More free practice: fieldbooklearning.com/ca/practice/grade-8/is-the-triangle-acute-right-or-obtuse/

Answer key: Is the triangle acute, right or obtuse?

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