SIMILARITY & TRIGONOMETRY

OVERVIEW

Trigonometry is introduced as a special case of similarity within right-angled
triangles linking to the introductory lesson in Year 9. Emphasis is placed throughout the steps on linking the trig functions to ratios, rather than just functions.

There is sufficient time for Foundation classes to revise Pythagoras Theorem in depth.

Lesson Resources

Similarity & enlargment

Lesson 1 – Enlargement positive scale factors

Lesson 2 – Enlarging from a point

Lesson 3 – Enlargement fractional scale factors

Lesson 4 – Enlargement negative scale factors (Higher)

Lesson 5– Similar Shapes

Lesson 6 – Similar Triangles and Parallel Lines

Lesson 7 – Similar Area (Higher)

Lesson 8 – Similar Volume (Higher)

Trigonometry

Lesson 9 – The Sine Ratio

Lesson 10 – Using all three ratios to find missing lengths

Lesson 11 – Using all three ratios to find missing angles

Lesson 12 – Working with exact values (Higher)

Lesson 13 – Pythagoras or Trigonometry?

Lesson 14 – Solving area problems with Trigonometry

Lesson 15 – The Sine Rule (Higher only)

Lesson 16 – The Cosine Rule (Higher only)

Lesson 17 – Sine or Cosine Rule? (Higher only)

Lesson 18 – Bearings and Trigonometry (Higher only)

Lesson 19 – Area of non-right angled triangles (Higher only)