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Grade 12Curriculum · Maths: geometry

Sine Rule, Cosine Rule and Triangle Area Worksheets

Practise trigonometry in non-right triangles.

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Exercise type
Triangle area, sine and cosine rules
Grade
12 (ages 17–18)
Difficulty
Easy
Number of tasks
20
Task format
Calculations
Paper size
A4
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Triangle area, sine and cosine rules · Grade 12

Name: ____________________
Example: how to solve it
1.

Find the area: sides 10 cm and 10 cm, angle between them 30° (1 decimal)

2.

Find the area: sides 11 cm and 13 cm, angle between them 120° (1 decimal)

3.

Find the area: sides 19 cm and 6 cm, angle between them 30° (1 decimal)

4.

Find the area: sides 6 cm and 15 cm, angle between them 30° (1 decimal)

5.

Find the area: sides 19 cm and 10 cm, angle between them 90° (1 decimal)

6.

Find the area: sides 11 cm and 13 cm, angle between them 60° (1 decimal)

7.

Find the area: sides 18 cm and 4 cm, angle between them 45° (1 decimal)

8.

Find the area: sides 9 cm and 6 cm, angle between them 120° (1 decimal)

9.

Find the area: sides 12 cm and 6 cm, angle between them 120° (1 decimal)

10.

Find the area: sides 13 cm and 10 cm, angle between them 30° (1 decimal)

11.

Find the area: sides 17 cm and 20 cm, angle between them 150° (1 decimal)

12.

Find the area: sides 6 cm and 8 cm, angle between them 30° (1 decimal)

13.

Find the area: sides 16 cm and 10 cm, angle between them 90° (1 decimal)

14.

Find the area: sides 15 cm and 4 cm, angle between them 60° (1 decimal)

15.

Find the area: sides 11 cm and 15 cm, angle between them 120° (1 decimal)

16.

Find the area: sides 8 cm and 16 cm, angle between them 30° (1 decimal)

17.

Find the area: sides 13 cm and 11 cm, angle between them 150° (1 decimal)

18.

Find the area: sides 20 cm and 10 cm, angle between them 60° (1 decimal)

19.

Find the area: sides 13 cm and 9 cm, angle between them 150° (1 decimal)

20.

Find the area: sides 19 cm and 19 cm, angle between them 90° (1 decimal)

Answer key

  1. 1. 25 cm²
  2. 2. 61.9 cm²
  3. 3. 28.5 cm²
  4. 4. 22.5 cm²
  5. 5. 95 cm²
  6. 6. 61.9 cm²
  7. 7. 25.5 cm²
  8. 8. 23.4 cm²
  9. 9. 31.2 cm²
  10. 10. 32.5 cm²
  11. 11. 85 cm²
  12. 12. 12 cm²
  13. 13. 80 cm²
  14. 14. 26 cm²
  15. 15. 71.4 cm²
  16. 16. 32 cm²
  17. 17. 35.7 cm²
  18. 18. 86.6 cm²
  19. 19. 29.2 cm²
  20. 20. 180.5 cm²

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About this generator

Easy: area ½ab·sin C, medium: cosine rule, hard: sine rule. The answer key is calculated by the website. No sign-up needed.

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