The Law

1
Chapter 7 Measurement
7.7
The Law Of Sines
7.7.1
MATHPOWERTM 10, WESTERN EDITION
2
The Law of Sines
An oblique triangle is a triangle that does not
contain a right angle.
7.7.2
3
Applying the Law of Sines
600
c
1800- (750 450) 600
c 12.25
7.7.3
4
Applying the Law of Sines- How high is the
balloon?
b sin1030 200 sin500
b 154.4 m
190
154.4 m
d sin190 154.4 sin 640
b
830
d
d 426.14 m
c
7.7.4
5
Applying the Law of Sines
Stan observes that the angle of elevation of a
plane is 510. At the same time, Paul observes it
to be 340. They are 340 m apart. How far is each
person from the plane? How high is the plane?
340
510
340 m
7.7.5
6
How high is the plane? The Solution
A
950
b
c
b 265.24 m Paul is 265.24 m away.
340
D
510
340 m
B
C
AD 190.85 sin 51 148.32 m The plane is
148.32 m high.
c 190.85 m Stan is 190.85 m away.
7.7.6
7
Finding the Area of a Triangle
Find the area of the triangle ABC.
B
880
22 cm
a 22 sin 680 a 20.40 cm
a
680
240
A
54.06 cm
C
b
Area 551.36 cm2
b 54.06 cm
7.7.7
8
Assignment
Pages 347 and 348 1 - 4, 7, 8 9, 11, 14, 17, 18,
19
7.7.8