cosine rule
TRANSCRIPT
Cosine RuleC
AB
ab
c
a A = + - 2 Cosb bc c2 2 2
C
AB
5 cm
7 cm
x cm
Find the length of side x
60o
a = x
o
a
Cosine RuleC
AB
ab
c
a A = + - 2 Cosb bc c2 2 2
C
AB
5 cm
7 cm
x cm
Find the length of side x
60o
a = x
b = 5
a
b
Cosine RuleC
AB
ab
c
a A = + - 2 Cosb bc c2 2 2
C
AB
5 cm
7 cm
x cm
Find the length of side x
60o
a = x
b = 5
c = 7
a
b
c
Cosine RuleC
AB
ab
c
a A = + - 2 Cosb bc c2 2 2
C
AB
5 cm
7 cm
x cm
Find the length of side x
60o
a = x
b = 5
c = 7
<A = 60
o
a
b
c
Cosine RuleC
AB
ab
c
a A = + - 2 Cosb bc c2 2 2
C
AB
5 cm
7 cm
x cm
Find the length of side x
60o
a = x
b = 5
c = 7
<A = 60
o
a
b
c
Cosine RuleC
AB
ab
c
a A = + - 2 Cosb bc c2 2 2
C
AB
5 cm
7 cm
x cm
Find the length of side x
60o
a = x
b = 5
c = 7
<A = 60
o
a
b
c
𝑥2=52+72−2×5×7×𝐶𝑜𝑠60
Cosine RuleC
AB
ab
c
a A = + - 2 Cosb bc c2 2 2
C
AB
5 cm
7 cm
x cm
Find the length of side x
60o
a = x
b = 5
c = 7
<A = 60
o
a
b
c
𝑥2=52+72−2×5×7×𝐶𝑜𝑠60
¿
Cosine RuleC
AB
ab
c
a A = + - 2 Cosb bc c2 2 2
C
AB
5 cm
7 cm
x cm
Find the length of side x
60o
a = x
b = 5
c = 7
<A = 60
o
a
b
c
𝑥2=52+72−2×5×7×𝐶𝑜𝑠60
¿𝑥2=74−35
Cosine RuleC
AB
ab
c
a A = + - 2 Cosb bc c2 2 2
C
AB
5 cm
7 cm
x cm
Find the length of side x
60o
a = x
b = 5
c = 7
<A = 60
o
a
b
c
𝑥2=52+72−2×5×7×𝐶𝑜𝑠60
¿𝑥2=74−35𝑥2=39
Cosine RuleC
AB
ab
c
a A = + - 2 Cosb bc c2 2 2
C
AB
5 cm
7 cm
x cm
Find the length of side x
60o
a = x
b = 5
c = 7
<A = 60
o
a
b
c
𝑥2=52+72−2×5×7×𝐶𝑜𝑠60
¿𝑥2=74−35𝑥2=39
𝑥=√39
Cosine RuleC
AB
ab
c
a A = + - 2 Cosb bc c2 2 2
C
AB
5 cm
7 cm
x cm
Find the length of side x
60o
a = x
b = 5
c = 7
<A = 60
o
a
b
c
𝑥2=52+72−2×5×7×𝐶𝑜𝑠60
¿𝑥2=74−35𝑥2=39
𝑥=√39𝑥=6.24 𝑐𝑚