Non-Right-Angled Triangles (Edexcel AS Maths): Revision Note

Exam code: 8MA0

Non-right-angled triangles

What is the sine rule, cosine rule and area rule for non-right-angled triangles?

  • The Sine Rule, Cosine Rule and Area Formula can be used for ANY type of triangle

  • They can help us calculate missing side lengths, angles and area

Non-Right-Angled Triangles Diagram 1a, A Level & AS Level Pure Maths Revision Notes

 

Non-Right-Angled Triangles Diagram 1b, A Level & AS Level Pure Maths Revision Notes

 

Non-Right-Angled Triangles Diagram 1c, A Level & AS Level Pure Maths Revision Notes

 

Non-Right-Angled Triangles Diagram 1d, A Level & AS Level Pure Maths Revision Notes

 

How do I know which rule to use?

Non-Right-Angled Triangles Diagram 2, A Level & AS Level Pure Maths Revision Notes
  • Once you know which rule to use, simply label your triangle, substitute in the values and rearrange if necessary

Examiner Tips and Tricks

  • If you are given two angles in a triangle, finding the missing angle by subtracting from 180° might help.

  • Make sure you are careful to pick the correct rule to use, you’ll need to remember all the rules as they aren’t in the formula booklet.

  • Make sure your calculator is in degree mode (D).

  • Always check your answers are sensible…

    • Have I remembered to square root at the end?

    • Have I remembered to use -1?

  • Check if the question asks you to round your answer.

Worked Example

Non-Right-Angled Triangles Example Diagram, A Level & AS Level Pure Maths Revision Notes

 

Non-Right-Angled Triangles Example Solution, A Level & AS Level Pure Maths Revision Notes
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Lucy Kirkham

Author: Lucy Kirkham

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Lucy has been a passionate Maths teacher for over 12 years, teaching maths across the UK and abroad helping to engage, interest and develop confidence in the subject at all levels.Working as a Head of Department and then Director of Maths, Lucy has advised schools and academy trusts in both Scotland and the East Midlands, where her role was to support and coach teachers to improve Maths teaching for all.