IGCSE · Mathematics · Chapter 20

Ch 20 Pythagoras and Trigonometry: complete notes

Neat, exam-ready notebook-style notes for Ch 20 Pythagoras and Trigonometry, following the Cambridge IGCSE syllabus, Core and Extended. This chapter is part of the complete IGCSE Mathematics 0580 Complete Notes: All 26 Chapters, Core and Extended (Cambridge 2025–2027).

Test yourself: Chapter 20 online MCQ test, free: 10 questions, 15 minutes, instant score and solutions →

What you get in the pack

• All 26 chapters of the Cambridge IGCSE Mathematics 0580 syllabus (exams 2025–2027): number, algebra, graphs, differentiation, functions, coordinate geometry, geometry, mensuration, trigonometry, transformations, vectors, probability and statistics
• Every syllabus statement covered in order, each marked Core or Extended, with clear notes and diagrams drawn for these notes
• 8 worked examples in every chapter, plus non-calculator and calculator skills
• Common mistakes taken from Cambridge examiner reports, so you know where marks are lost
• 20 quick-check MCQs per chapter with answers and explanations
• Original exam-style questions in the style of Paper 2 (non-calculator) and Paper 4 (calculator) for Extended, Paper 1 and Paper 3 for Core, with full mark schemes (no past-paper reprints)
• Quick-reference sheet and an "I can" checklist at the end of every chapter
• Colour PDF and a black and white copy of every chapter for printing
• Independent notes; not endorsed by or affiliated with Cambridge University Press & Assessment

All chapters in this pack

1. Ch 1 Number: Types, Sets and Fractions
2. Ch 2 Indices, Standard Form and Surds
3. Ch 3 Accuracy, Calculators, Time and Money
4. Ch 4 Ratio, Proportion and Rates
5. Ch 5 Percentages, Growth and Decay
6. Ch 6 Algebraic Manipulation
7. Ch 7 Equations and Formulas
8. Ch 8 Inequalities
9. Ch 9 Sequences
10. Ch 10 Direct and Inverse Proportion
11. Ch 11 Graphs in Practical Situations
12. Ch 12 Graphs of Functions and Sketching Curves
13. Ch 13 Differentiation
14. Ch 14 Functions
15. Ch 15 Coordinate Geometry
16. Ch 16 Geometrical Terms, Constructions and Symmetry
17. Ch 17 Angles and Similarity
18. Ch 18 Circle Theorems
19. Ch 19 Mensuration
20. Ch 20 Pythagoras and Trigonometry
21. Ch 21 Sine Rule, Cosine Rule and 3D Trigonometry
22. Ch 22 Transformations
23. Ch 23 Vectors
24. Ch 24 Probability
25. Ch 25 Statistics: Averages, Charts and Scatter Diagrams
26. Ch 26 Cumulative Frequency and Histograms