## Trigonometry By the end of this topic you will be able to answer this question and other similar problems.

During the topic you will explore the relationships between the sides of right-angled triangles and use the knowledge gained to solve problems involving the sides and angles of right-angled triangles.

### 24 Responses

1. Wednesday 3 September, Period 5

Work in groups to compare sides in right-angled triangles. All start with a 30º-60º-90º triangle, any size.

Note and discuss findings.

2. NH’s group were first to discover that the hypotenuse was double the side opposite the 30º angle.

Shared with class and all agreed. Looked at ratios of other sides and discovered similar results.

3. Thursday 4 September, Period 4

Recap what we discovered yesterday and then look at right triangles with different angles in groups.

Create a table of ratios for angles 5º to 85º from class results. Use the table to calculate lengths and angles.

4. Class produced superb table of values from scale drawings. All values were within a few thousandths of actual values!

5. Friday 5 September, Period 5

Use trig tables to calculate sides and angles.

6. Done and introduced calculator.

7. Tuesday 9 September, Period 2

Worked examples of finding angle and sides.

Trigonometry Problems worksheet, Q1-2.

8. Q1 and most of Q2 complete

9. Wednesday 10 September, Period 5

Space Trig starter questions (height of shuttle and depth of moon crater).

Complete trig worksheet.

10. Done but some need further practice to become more confident and fluent.

11. Thursday 11 September, Period 4

Mixed problems worksheet.

12. Much better progress today, most of class completed most of (extensive) worksheet.

13. Friday 12 September, Period 5

Return factors homework. Set new homework on trigonometry.

Look at angles of elevation and depression problems.
Go outside to calculate height of school and other objects using trig if weather OK.

If weather poor do Trigonometry – Cooperative Logic Problems activity.

14. Weather lovely!

Watched Maths4Real video on Tan Ratio to set scene.
Pupils answered questions while watching and made note of how to calculate the height of an object.
Class then went outside and calculated height of main building to be 9.5m.

15. Tuesday 16 September, Period 3

Recap what we have learned to date. Worked examples followed by applyibg trig to solve problems.

MiA Ex10.1

16. Used ‘show-me’ boards to recap key points then started Ex10.1.

17. Wednesday 17 Spetember, Period 5

Complete Ex10.1, leave time for Trigonometry – Cooperative Logic Problems activity if possible.

18. Non-calculator questions starter & discussion. Looked at a selection of trig problems then worked on Ex10.1.

Did not do coop task as felt needed more time to do proper justice.

19. Thursday 18 September, Period 4

Continue trig problems, Ex10.3 for first half of period then – Cooperative Logic Problems activity.

Homework due today.

20. Friday 19 September, Period 5

Trig exam questions, model solutions in groups then share with class.

21. Tuesday 23 September, Period 2

Review Trig topic, get class to summarise key points then create problems (with ‘stories’) for each group to solve.

22. Some very interesting problems created!

23. Thursday 25 September

group practical problems using trig:

1. Determine height of cherry trees
2. Check length of 100m running track
3. Calculate total length of playing fields

Will need clipboards, clinometers, tapes.

24. Good group work. Trees calculated fairly accurately.
100m track very sensitive to angle of depression measured.
Total length of field very difficult to calculate due to very small angle (approx 1 degree)

Good discussion at end on causes of error/difficulty.