Reviewing

1
Chapter 7 Measurement
7.4
Reviewing Trig Ratios
7.4.1
MATHPOWERTM 10, WESTERN EDITION
2
The Primary Trigonometric Ratios
q
Hypotenuse
Hypotenuse
Hypotenuse
Hypotenuse
Hypotenuse
Opposite
Opposite
Opposite
Opposite
Opposite
Adjacent
q
Adjacent
Adjacent
Adjacent
Adjacent
Opposite
Opposite Hypotenuse
Opposite Adjacent
Sine q
Tan q
Soh Cah Toa
Adjacent Hypotenuse
Cosine q
7.4.2
3
Determining Values of Primary Trigonometric Ratios
7.4.3
4
Trigonometric Ratios of Acute Angles
Find each of the following, to three decimal
places
d) tan 140 e) sin 590 f) cos 820
0.249
a) sin 640 b) cos 280 c) tan 480
0.899
0.857
0.883
1.111
0.139
Find the measure of each angle, to the nearest
degree
d) tan A 0.7563 e) sin B 0.5421 f) cos C
2
370
190
a) sin A 0.3214 b) cos B 0.6541 c) tan C
1.2312
330
490
510
undefined
7.4.4
5
Finding the Length of an Unknown Side
x 16 Tan 34 x 10.8 cm
y 19.3 cm
x 27 sin42 x 18.1 cm
y 27 cos42 y 20.1 cm
7.4.5
6
Find the Measure of the Unknown Angle
c2 a2 b2
262 x2 192 x2 262 - 192 x2 315 x
17.7 cm
q 43.00
c2 a2 b2 x2 142 222 x2 680 x 26.1 cm
q 32.50
7.4.6
7
Solving a Right Triangle
To solve a right angle triangle means to find
all missing sides and angles.
A
510
x
y
x 33.5 cm
y 21.1 cm
B
C
26 cm
AB 33.5 cm AC 21.1 cm B 390
7.4.7
8
Solving Problems Involving Trigonometry- Problem 1
A tree casts a shadow 12 m long. The angle to
the top of the tree from the end of the shadow
is 680. Find the height of the tree.
x 12 sin 68 x 11.13 m
The tree is 11.13 m tall.
7.4.8
9
Solving Problems Involving Trigonometry- Problem 2
A 12 m ladder is leaned up against a brick wall.
If the ladder forms an angle of 360 with the
wall, find the height of the wall.
360
12 m
x
x 12 cos360 x 9.71 m
The wall is 9.71 m high.
7.4.9
10
Solving Problems Involving Trigonometry- Problem 3
Find the height of the cliff.
y 70 cos500 y 45.0 m
x
45
x 45 Tan400 x 37.76 m
y
The cliff is 37.76 m high.
7.4.10
11
Assignment
Suggested Questions
Page 329 4 1, 2 5 1 - 6 6 1 - 6
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