Level 4 · Mathematics M4.3

Pythagoras and trigonometry

Find missing sides and angles in triangles, starting with right angled ones.

Learn why the squares on the sides of a right angled triangle add up, and use that to find lengths. Then meet sine, cosine and tangent, find sides and angles with a calculator, learn the exact values for 30°, 45° and 60°, and solve any triangle with the sine rule, the cosine rule, area and bearings.

Start readingM4.3.1 Pythagoras' theorem

8 chapters. Your place is kept on this device only.

You are ready for this book if

You can solve 3x = 12 and work out √(9 + 16).

Contents

  1. 1Pythagoras' theorem, readunderstood
  2. 2Using Pythagoras, readunderstood
  3. 3Opposite, adjacent and hypotenuse, readunderstood
  4. 4Sine, cosine and tangent, readunderstood
  5. 5Finding angles, readunderstood
  6. 6Exact values, readunderstood
  7. 7The sine rule and the cosine rule, readunderstood
  8. 8Area of any triangle, and bearings, readunderstood

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For parents and teachers

For learners who can solve 3x = 12, work out √(9 + 16) and recognise a right angle. In many schools this fits teenagers of about 14 to 16, and adults who want to refresh triangle sums can start here too. Each chapter takes one or two sessions. A learner needs a scientific calculator, set to degrees. A learner can work alone: every exercise has its answer and the reason for it.

Strand: Shape and space. Written and drawn by attnom. Free to read, print and share.