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Mathematics
Edexcel GCSE Mathematics
Geometry and Measures
Mensuration and Calculation
Sine and Cosine Rules
Edexcel GCSE Mathematics · 1MA1
Sine and Cosine Rules
What you need to know
Apply the sine rule
a
sin
A
=
b
sin
B
=
c
sin
C
\frac{a}{\sin A} = \frac{b}{\sin B} = \frac{c}{\sin C}
s
i
n
A
a
=
s
i
n
B
b
=
s
i
n
C
c
to find unknown lengths and angles.
Apply the cosine rule
a
2
=
b
2
+
c
2
−
2
b
c
cos
A
a^2 = b^2 + c^2 - 2bc \cos A
a
2
=
b
2
+
c
2
−
2
b
c
cos
A
to find unknown lengths and angles.
Revision notes
1
Sine and Cosine Rules
6 key terms
Practise with past papers
Key terms & definitions
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Area of a Triangle
