Trigonometry Chapter
Trigonometry
Surveying
Measure inaccessible distances70 ft
Bolt Circles
Trailer Hub
Micro Sprint Quick Change Sprocket Hub
Piston Travel
290
290
290
3.5”
Co
n
ro
d
=
4.
0”
70
Approaching top dead center (70 away).
1.
75
”
Co
n
ro
d
=
4
.0
”
At top dead center.
5.
75
”
1.75”
Preview of Trig…
Handout
Ruler
Protractor
84
mm
130
mm
155
mm
S
c t
84
mm
130
mm
155
mm
RATIO
=
0.5
42
Angle sine cosine tangent
31 0.515 0.857 0.601
32 0.530 0.848 0.625
33 0.545 0.839 0.649
34 0.559 0.829 0.675
35 0.574 0.819 0.700
84
mm
130
mm
155
mm
RATIO
=
0.8
39
Angle sine cosine tangent
31 0.515 0.857 0.601
32 0.530 0.848 0.625
33 0.545 0.839 0.649
34 0.559 0.829 0.675
35 0.574 0.819 0.700
84
mm
130
mm
155
mm
RATIO
=
0.6
46
Angle sine cosine tangent
31 0.515 0.857 0.601
32 0.530 0.848 0.625
33 0.545 0.839 0.649
34 0.559 0.829 0.675
35 0.574 0.819 0.700
16
166
mm
27
°
?
?
166
mm
27
°
Angle sine cosine tangent
27 0.454 0.891 0.510
0.454
?
166
=
166
mm
27
°
Angle sine cosine tangent
27 0.454 0.891 0.510
0.891
?
166
=
?
Trigonometry Section 2
Naming the Sides of a Right
Triangle
hypotenuse leg
Naming the Sides of a Right
Triangle
Names of the Sides
•hypotenuse •opposite •adjacent
A
Naming the Sides of a Right
Triangle
Names of the Sides
•hypotenuse •opposite •adjacent
A
hypotenuse
Naming the Sides of a Right
Triangle
Names of the Sides
•hypotenuse •opposite •adjacent
B
hypotenuse
Naming the Sides of a Right
Triangle
A hypotenuse
Practice Set 2
Page 11
Trigonometry Section 2
Use trig ratios to solve problems
sine
ratio
cosine
ratio
tangent
ratio
A
Trigonometry Ratios
A
A
hypotenuse
opposite
sin A =
hypotenuse
adjacent
cos A =
adjacent
opposite
Practice
Trig Worksheet #1
“Trig Ratios”
Ruler (mm)
Protractor
Practice Set 3
page 16
#3, 4 only
50 mm 87 mm 100 mm
50
100 0.5 87
100 0.87 50
87 0.575
28 0.469 0.883 0.532
29 0.485 0.875 0.554
30 0.500 0.866 0.577
Angle sine cosine tangent
31 0.515 0.857 0.601
32 0.530 0.848 0.625
30°
opposite hypote
nuse
31 mm 24 mm 39 mm
3 1
39
0.795
24
39
0.61
5
3 1
24
1.29
2
52°
Angle sine cosine tangent
48 0.743 0.669 1.111
49 0.755 0.656 1.150
50 0.766 0.643 1.192
51 0.777 0.629 1.235
52 0.788 0.616 1.280
53 0.799 0.602 1.327
54 0.809 0.588 1.376
opposite
hypo tenu
se
38 mm 117 mm 123 mm
3 8
123
0.309
11 7
123
0.95
1
38
18°
117
0.32
5
Angle sine cosine tangent
16 0.276 0.961 0.287
17 0.292 0.956 0.306
18 0.309 0.951 0.325
19 0.326 0.946 0.344
20 0.342 0.940 0.364
opposite hypotenu
se
Calculator Skills
Calculator
Angle sine cosine tangent
0 0.000 1.000 0.000
2 0.035 0.999 0.035
4 0.070 0.998 0.070
6 0.105 0.995 0.105
8 0.139 0.990 0.141
10 0.174 0.985 0.176
12 0.208 0.978 0.213
14 0.242 0.970 0.249
16 0.276 0.961 0.287
18 0.309 0.951 0.325
20 0.342 0.940 0.364
22 0.375 0.927 0.404
24 0.407 0.914 0.445
26 0.438 0.899 0.488
28 0.469 0.883 0.532
Check Your Calculator
D
DEG
The calculator display
must show either:
D
or
CALCULATOR
Angle
sine
cosine
tangent
31
0.515
0.857
0.601
32
0.530
0.848
0.625
33
0.545
0.839
0.649
34
0.559
0.829
0.675
35
0.574
0.819
0.700
36
0.588
0.809
0.727
37
0.602
0.799
0.754
38
0.616
0.788
0.781
39
0.629
0.777
0.810
40
0.643
0.766
0.839
sine of 35 =
0.574
sin35 =
sin 3 5 =
0.573576436 sin
3 5
Angle
sine
cosine
tangent
31
0.515
0.857
0.601
32
0.530
0.848
0.625
33
0.545
0.839
0.649
34
0.559
0.829
0.675
35
0.574
0.819
0.700
36
0.588
0.809
0.727
37
0.602
0.799
0.754
38
0.616
0.788
0.781
39
0.629
0.777
0.810
40
0.643
0.766
0.839
tangent of 40 =
0.839
tan40 =
tan 4 0 =
0.839099631 tan
4 0
CALCULATOR
Angle
sine
cosine
tangent
61
0.875
0.485
1.804
62
0.883
0.469
1.881
63
0.891
0.454
1.963
64
0.899
0.438
2.050
65
0.906
0.423
2.145
66
0.914
0.407
2.246
67
0.921
0.391
2.356
68
0.927
0.375
2.475
69
0.934
0.358
2.605
70
0.940
0.342
2.747
What angle has a cosine ratio of 0.423?
65
cos A = 0.423
64.97586456
cos . 4 =
2nd . 4 2 3 2nd2 3 cos
cos-10.423
Angle
sine
cosine
tangent
61
0.875
0.485
1.804
62
0.883
0.469
1.881
63
0.891
0.454
1.963
64
0.899
0.438
2.050
65
0.906
0.423
2.145
66
0.914
0.407
2.246
67
0.921
0.391
2.356
68
0.927
0.375
2.475
69
0.934
0.358
2.605
70
0.940
0.342
2.747
What angle has a sine ratio of 0.940?
70
sin A = 0.940
70.05155641
sin . 9 =
2nd. 9 4 0 2nd4 0sin
sin-10.940
Practice
Trig Worksheet #2
“Calculator Skills”
Problems 1-3
Calculator Skills
Review of Basics
Review of Skills
Determine the Trig Ratio
sin42
= _____
cos10
= ______
tan85
= ______
0.6691
0.9848
11.4301
42 sin
sin 42 = or
10 cos
cos 10 = or
Angle sine cosine tangent
31 0.515 0.857 0.601
32 0.530 0.848 0.625
33 0.545 0.839 0.649
34 0.559 0.829 0.675
35 0.574 0.819 0.700
Review of Skills
Determine the Angle from a Ratio
sin
A
= 0.9063
Angle
A
= _______
cos
B
= 0.866
Angle
B
= _______
tan
A
= 1.1918
Angle
A
= _______
65
30
50
2nd sin .9063 = .9063 2nd sin
or
Angle sine cosine tangent
31 0.515 0.857 0.601
32 0.530 0.848 0.625
33 0.545 0.839 0.649
34 0.559 0.829 0.675
35 0.574 0.819 0.700
Calculator Skills Part II
Evaluate Trig Formulas
Three Possibilities…
opp hyp
adj A
4”
7”
32
x 12 ft
opp hyp
adj
29
x
9.5”
opp
hyp
adj
tan A= 4”
cos 29
Three Trig Setups
How to Solve…opp hyp
adj A
4”
7”
32
x 12 ft
opp hyp adj 29 x 9.5” opp hyp adj
A = 29.7
tan A= 4” 7”
tan A= 0.5714
A = tan-1(0.5714)
sin 32= x 12 ft
(12 ft)(0.5299) = x
(12 ft) (12 ft)
6.4 ft = x
cos 29= 9.5” x (x) (x)
cos 29= 9.5” (x)
cos 29
x = 9.5” cos 29
x = 10.9”
cos 29° =
9.5
x
x
= 10.9”
Calculator Skills Worksheet
#4, Row C
Calculator Skills Worksheet
#4, Row D
Calculator Skills Worksheet
Practice
Trig Worksheet #2
“Calculator Skills”
Trigonometry - Section 2
Solving Right Triangles using Trig
Memory Device
SOH CAH TOA
If you decide that using trig is a good idea to solve a
Memory Device
SOH CAH TOA
S
OH
C
AH
T
OA
S
OH
C
AH
T
OA
sin
e
co
sin
e
ta
ng
en
t
opp
Trigonometry - Section 2
Solving Right Triangles using Trig
•
Establish a consistent technique to
Technique
for Solving Right Triangles with Trigopp hyp
adj
A
4”
7”
A = 29.7
tan A= 4” 7”
S
OH
C
AH
T
OA
Worksheet 3
Rehearse the five steps to solve a trig problem. Goal – Determine the measure of an angle. You will need – Ruler, protractor, calculator.
opp
adj hyp
24
mm
71
mm
SOH CAH TOA
24 71
A =
Technique
for Solving Right Triangles with Trig 32 x 12 ft opp hyp adj 29 x 9.5” opp hyp adjsin 32= x 12 ft
(12 ft)(0.5299) = x
6.4 ft = x
9.5” cos 29
x = 10.9” SOH CAH TOA SOH CAH TOA
x =
Worksheet 4
Rehearse the five steps used to solve a trig
problem.
Goal – Use trig to determine the length of a
specified side.
You will need – Ruler, protractor, calculator.
sin A= opp
31°
opp
adj
hyp SOH CAH TOA
99
31
tan
x
59.5
adj
opp
A
Additional Practice