1. Designed by:
Emily Freeman McEachern High School 2400 New Macland Rd Powder Springs, GA  30127

2. Session 17
Warm – up: Find the missing measures. Write all answers in radical form.
30°
45° x 7 10 z
45° w
60° y

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

4. The Trigonometric Functions
SINE
COSINE
TANGENT

5. SINE
Prounounced “sign”

6. Prounounced “co-sign”
COSINE
Prounounced “co-sign”

7. Prounounced “tan-gent”

8. Represents an unknown angle
Greek Letter q
Prounounced “theta”
Represents an unknown angle

9. hypotenuse
hypotenuse
opposite
opposite
adjacent
adjacent

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

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

12. Sin
SOHCAHTOA
Opp
Hyp
Cos
Adj
Hyp
Tan
Opp
Adj
Old Hippie

13. Finding sin, cos, and tan

14. SOHCAHTOA 10
opp
hyp 8 6
adj

15. 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

16. ? 5 4 3 Pythagorean Theorem: (3)² + (4)² = c² 5 = c
Find the values of the three trigonometric functions of . ?
Pythagorean Theorem: 5 4
(3)² + (4)² = c²
5 = c 3

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). B
24.5
8.2 A
23.1

18. To use a calculator… first be sure your calculator is in “degree” mode
Angle decimal Use the sin, cos, tan keys on your calculator Ex. Sin 65= ______ Type sin, 65, enter Round the decimal to 4 places
Decimal angle Use sin-1, cos-1, or tan-1 You need to use the 2nd key here. Ex. Cos A = Type 2nd, cos, .2493, enter Round degrees to the nearest tenth.

19. Calculator Practice
Use a calculator to find each value. Round to the nearest ten-thousandths.
sin 92.4 =
tan 27.5 =
cos 64.8 =
Find the measure of the angle to the nearest tenth of a degree.
sin B = angle =
tan A = angle =
cos R = angle =

20. Finding a side

21. Ex.
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
y = 50 ( )

22. Ex. 5
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