1. Find the missing measures. Write all answers in radical form.
Warm – up Session 17
Find the missing measures. Write all answers in radical form. x
30° 10
30 z
45 3
60 y
60°
45 y

2. Agenda for today February 15th, 2017
Warm-up
Notebook entry
PowerPoint 9.5 & 9.6
Create SOHCAHTOA Acronym
Human Triangles
Practice
Tuesday
TEST
Right Triangles

3. Questions over special right triangles ws?

4. You should be able to… Identify the trig ratios
Use trig ratios to solve for a missing side
Use information in a word problem to determine how to use trig to solve it.

5. The Trigonometric Functions we will be looking at
SINE
COSINE
TANGENT

6. The Trigonometric Functions
SINE
COSINE
TANGENT

7. SINE Pronounced “sign”
Introduce the students to the trig buttons on the calculators. This is a good time to have them find the sin of 30 degrees, 60 degrees, 90 degrees….

8. COSINE
Pronounced “co-sign”

9. Pronounced “tan-gent”

10. Represents an unknown angle
Greek Letter q
Prounounced “theta”
It’s the variable of angles.
Represents an unknown angle

11. hypotenuse hypotenuse opposite opposite adjacent adjacent
Now is the time to do human triangles.
adjacent
adjacent

12. We need a way to remember all of these ratios…

13. Some
Old
Hippie
Came A
Hoppin’
Through
Our
Old Hippie
Apartment

14. Old Hippie Sin Opp Hyp Cos Adj Hyp Tan Opp Adj SOHCAHTOA
This is just one way. If there is time, see if the students can come up with their own acronym
Opp
Adj
Old Hippie

15. Finding sin, cos, and tan. (Just writing a ratio or decimal.)

16. 10.8 9 A 6 Find the sine, the cosine, and the tangent of angle A.
Give a fraction and decimal answer (round to 4 places).
10.8 9 A 6

17. 24.5 8.2 23.1 Find the sine, the cosine, and the tangent of angle A
Give a fraction and decimal answer (round to 4 decimal places).
8.2 A
23.1

18. Finding a side. (Figuring out which ratio to use and getting to use a trig button.)

19. Ex: 1. Figure out which ratio to use. Find x
Ex: 1 Figure out which ratio to use. Find x. Round to the nearest tenth.
20 m x
tan 20 55 )

20. Ex: 2 Find the missing side. Round to the nearest tenth.

21. Ex: 3 Find the missing side. Round to the nearest tenth.
20 ft x

22. Ex: 4 Find the missing side. Round to the nearest tenth.
80 ft x
tan 80  ( 72 ) ) =

23. Ex: 5
A surveyor is standing 50 feet from the base of a large tree. The surveyor measures the angle of elevation to the top of the tree as 71.5°. How tall is the tree?
tan 71.5° ?
tan 71.5°
71.5°
y = 50 (tan 71.5°) 50

24. Ex. 6
A person is 200 yards from a river. Rather than walk directly to the river, the person walks along a straight path to the river’s edge at a 60° angle. How far must the person walk to reach the river’s edge?
cos 60°
x (cos 60°) = 200
200
60° x x
X = 400 yards

25. Finding an angle. (Figuring out which ratio to use and getting to use the 2nd button and one of the trig buttons.)

26. Ex. 1: Find . Round to four decimal places.
tan
17.2 9 )
17.2 9
Make sure you are in degree mode (not radians).

27. Ex. 2: Find . Round to three decimal places.7
2nd
cos 7 23 ) 23
Make sure you are in degree mode (not radians).

28. Ex. 3: Find . Round to three decimal places.
200
400
2nd
sin
200
400 )
Make sure you are in degree mode (not radians).

29. When we are trying to find a side we use sin, cos, or tan.
When we are trying to find an angle
we use sin-1, cos-1, or tan-1.

30. Let’s see if we can answer..
How are trigonometric functions used to determine the measure of a missing side or a missing angle?

31. Practice work
Worksheets
9.5 & 9.6