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a
17 cm
320
1.
Warm Up April 18 and 19
Find the missing variables. Round to the nearest whole number.
20 m
x
18 m
6 m
b
2.
y
12 cm
320
rFind the radius and the area of the circle.
3.
Answers
2
1. 9
117
2. 64
2 19
3. 7
49
a cm
b cm
x
y m
r cm
a cm
12.3 Law of Sines
SAS Triangle Area Conjecture
em.between th angle theis
and sides twoof lengths theare and where
,sin2
1
formula by thegiven is trianglea of area The
C
ba
CabA
a
b
C
Example 1
Find the area of the triangle.
12”
11”
93°
2
1sin
21
12 11 sin 932
65.91
A ab C
A
A in
Law of Sines
c
C
b
B
a
A sinsinsin
b
c
a
A B
C
Example 2
Find e.
D
F
E
250 cm
59°
38°
sin sin
sin 59 sin 38
250
sin 59 250sin 38
250sin 38
sin 59179.56
D E
d e
e
e
e
e cm
Try this on your own ex3:
362 m
x
46o
76oNeed to find this angle hint: what do all the angles in a triangle add up to?
X=316.39 m
Example 4
Find the measure of angle B.
A
B
C150’
250’
68°1
sin sin
sin 68 sin
250 150
250sin 150sin 68
150sin 68sin
250
150sin 68sin
250
33.8
A B
a b
B
B
B
m B
m B
Example 5 – try on your own
51o
1417
x
X= 39.790
Homework
Page 637 # 1 – 11 skip 4
