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Angles in a triangle

Grade 10 math · Fieldbook Learning

Name ______________________ Date __________

The three angles add up to 180°.

  1. Two angles of a triangle are 77° and 79°. What is the third angle?
  2. Two angles of a triangle are 83° and 77°. What is the third angle?
  3. Two angles of a triangle are 34° and 99°. What is the third angle?
  4. Two angles of a triangle are 20° and 25°. What is the third angle?
  5. Two angles of a triangle are 66° and 20°. What is the third angle?
  6. Two angles of a triangle are 66° and 66°. What is the third angle?
  7. Two angles of a triangle are 88° and 21°. What is the third angle?
  8. Two angles of a triangle are 91° and 59°. What is the third angle?
  9. Two angles of a triangle are 69° and 44°. What is the third angle?
  10. Two angles of a triangle are 104° and 19°. What is the third angle?
  11. Two angles of a triangle are 56° and 27°. What is the third angle?
  12. Two angles of a triangle are 55° and 30°. What is the third angle?
  13. Two angles of a triangle are 66° and 63°. What is the third angle?
  14. Two angles of a triangle are 60° and 100°. What is the third angle?
  15. Two angles of a triangle are 85° and 23°. What is the third angle?
  16. Two angles of a triangle are 45° and 56°. What is the third angle?
  17. Two angles of a triangle are 74° and 15°. What is the third angle?
  18. Two angles of a triangle are 32° and 32°. What is the third angle?
  19. Two angles of a triangle are 58° and 43°. What is the third angle?
  20. Two angles of a triangle are 93° and 39°. What is the third angle?
More free practice: fieldbooklearning.com/ca/practice/grade-10/angles-in-a-triangle/

Answer key: Angles in a triangle

  1. 24°
  2. 20°
  3. 47°
  4. 135°
  5. 94°
  6. 48°
  7. 71°
  8. 30°
  9. 67°
  10. 57°
  11. 97°
  12. 95°
  13. 51°
  14. 20°
  15. 72°
  16. 79°
  17. 91°
  18. 116°
  19. 79°
  20. 48°