1. Trigonometry
Monday, 18 February 2019

2. An introduction to Trigonometry
A Power point for those who have never met trigonometry before.

3. An introduction to Trigonometry
Opposite A

4. An introduction to Trigonometry
Hypotenuse
Opposite A

5. An introduction to Trigonometry
Hypotenuse
Opposite A
Adjacent

6. Label each of the following triangles (i) (ii) (iii)
Example
Label each of the following triangles
(i) (ii) (iii) g d A f b a h i e A A c

7. Example
For the triangle below
Write down the lengths of the opposite and hypotenuse sides
Work out the ratio
Opposite = 8cm
Hypotenuse = 12cm
12cm
8cm
41.8°
c) Now work out the sin of 41.8° using the calculator
Sin 41.8°=0.6665

8. Right-angled Trigonometry
Opp
Hyp A
Adj

9. Example
Work out the lettered length in the triangle given below, giving your answer to 1 decimal place.
8 cm a
25°

10. Example
Work out the lettered length in the triangle given below, giving your answer to 1 decimal place.
15 m
48° b

11. Example
Work out the lettered length in the triangle given below, giving your answer to 2 decimal place.
15°
37 cm b

12. Example
Work out the length of AB in the triangle given below, giving your answer to 2 decimal place. A
56° C B
7 m

13. Example
For the triangle below
Write down the lengths of the Adjacent and hypotenuse sides
Work out the ratio
12cm
Adjacent = 7cm
Hypotenuse = 12cm
54.3°
7cm
c) Now work out the cos of 54.3° using the calculator
cos 54.3°=0.5835

14. Right-angled Trigonometry
Opp
Hyp A
Adj

15. Example
Work out the lettered length in the triangle given below, giving your answer to 1 decimal place.
10 cm
31° a

16. Example
Calculate the length of PQ in the triangle PQR P R
52 cm
32 Q

17. Example
Calculate the length XY in the triangle XYZ X Y
59
4.6 cm Z

18. Right-angled Trigonometry
Opp
Hyp A
Adj

19. Example
Work out the lettered length in the triangle given below, giving your answer to 1 decimal place.
4 cm
27° a

20. Example
Calculate the length XZ in the triangle XYZ, giving your answer correct to 3 significant figures.
4.6 cm Y Z
38 X

21. Example
Work out the length of AC in the triangle given below, giving your answer to 2 decimal place. A
56° C B
7 m