Year 9 - Maths
Problem solving with trigonometry
Trigonometry
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This pupil-friendly study guide includes a unit summary, clear notes, common mistakes, and quick questions with answers.
Unit Summary
In this unit pupils learn how to recognise the relationship between the unit circle and the trigonometric ratios of sine, cosine and tangent. Pupils then apply this knowledge to solve trigonometric problems.
Lesson Summary
You will learn to use your knowledge of trigonometry to solve problems.
Key Notes
- Sometimes there can be more than one valid approach to a problem.
- You should consider all the skills you have.
- Consider multiple approaches and take time to evaluate each.
- Keep the goal in mind throughout, remember what you are trying to find out.
Vocabulary To Learn
- Trigonometric ratios: The trigonometric ratios are ratios between each pair of lengths in a right-angled triangle.
Common Mistakes To Avoid
- Pupils may struggle to identify a right-angled triangle in the problem.
3 Quick Questions (With Answers)
1. Solve this in steps: explain the method from this lesson and why each step matters.
Sometimes there can be more than one valid approach to a problem. You should consider all the skills you have.
2. Use this key word in a maths sentence and explain it clearly. 'Trigonometric ratios'
The trigonometric ratios are ratios between each pair of lengths in a right-angled triangle. Use this word when showing your method, then check your final answer is reasonable.
3. Spot and fix this common maths mistake.
Mistake: Pupils may struggle to identify a right-angled triangle in the problem. Correction: Encourage pupils to sketch the question out and add any known right angles or perpendicular lines, as this may lead to a right-angled triangle.
More Lessons In This Unit
- Checking and securing understanding of Pythagoras' theorem Study Guide
- Checking and securing understanding of similar triangles Study Guide
- Choosing an appropriate method for finding lengths of a triangle Study Guide
- Choosing the right trigonometric ratio Study Guide
- Scaling the right-angled triangle from the unit circle Study Guide
- Sine and cosine ratios Study Guide
- Tangent ratio Study Guide
- The unit circle Study Guide
- Using the cosine ratio Study Guide
- Using the sine ratio Study Guide
- Using the tangent ratio Study Guide
Browse all guides in the Year 9 Maths guide library.