1. Aim: How do we review concepts of trigonometry?

2. Introduction Trigonometric Ratios
Trigonometry means “Triangle” and “Measurement”

3. Adjacent , Opposite Side and Hypotenuse of a Right Angle Triangle.

4. 
Opposite side
hypotenuse
Adjacent side

5. Pythagorean Theorem

6. 
hypotenuse
Adjacent side
Opposite side

7. Three Types Trigonometric Ratios
There are 3 kinds of trigonometric ratios we will learn.
sine ratio
cosine ratio
tangent ratio

8. Definition of Sine Ratio. Application of Sine Ratio.
Sine Ratios
Definition of Sine Ratio.
Application of Sine Ratio.

9. Definition of Sine Ratio.
Opposite sides 
Sin =

10. Definition of Sine Ratio.
Opposite side
hypotenuses
For any right-angled triangle
Sin =

11.  Exercise 1 In the figure, find sin  4 Opposite Side Sin = 7
hypotenuses 4 = 7
 =  (corr to 2 d.p.)

12. 35° Exercise 2 In the figure, find y y Opposite Side Sin35 =
hypotenuses
35° 11 y
Sin35 = 11
y = 11 sin35
y = (corr to 2.d.p.)

13. Cosine Ratios Definition of Cosine.
Relation of Cosine to the sides of right angle triangle.

14. Definition of Cosine Ratio.
Adjacent Side
Cos =

15. Definition of Cosine Ratio.
hypotenuses
Adjacent Side
For any right-angled triangle
Cos =

16.  Exercise 3 3 In the figure, find cos  adjacent Side cos = 8
hypotenuses 3 = 8
 =  (corr to 2 d.p.)

17. 42° Exercise 4 In the figure, find x 6 Adjacent Side Cos 42 =
hypotenuses x 6
Cos 42 = x 6
x =
Cos 42
x = (corr to 2.d.p.)

18. Tangent Ratios Definition of Tangent.
Relation of Tangent to the sides of right angle triangle.

19. Definition of Tangent Ratio.
Opposite Side 
Adjacent Side
For any right-angled triangle
tan =

20.  Exercise 5 3 In the figure, find tan  Opposite side 5 tan =
adjacent Side  3 = 5
 =  (corr to 2 d.p.)

21. 22 Exercise 6 In the figure, find z z Opposite side tan 22 =
adjacent Side 5 5
tan 22 = z 5
z =
tan 22
z = (corr to 2 d.p.)

22. Make Sure that the triangle is right-angled
Conclusion
Make Sure that the triangle is right-angled

23. END