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2-D Trigonometry
� Consider a triangle ABC : 1 . 2 .
3 . sin A sin B a b
� or � : Sine rule a b sin A sin B
2 2 2 a � b � c � 2bc cos A
2 2 2 b �c �a or cos A � : Cosine rule
2bc
1 absin
C : Area of the triangle ABC
2
� Consider a sector OPRQ with centre O , radius r and �POQ � � :
�
2� r � 360 � 360
: Arc length PRQ
2
� r � : Area of the sector OPRQ
�r
� 1 � � r sin�
: Area of the segment PRQ
360 2
2 2
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Areas and Volumes
� For a cube of side length l : 1 . 2 .
2
6l : Total surface area
3 l : Volume
� For a cuboid of side lengths a , b and c : 1 . 2 ( ab �bc � ac)
: Total surface area
2 . abc : Volume
� For a prism of height h and cross-sectional area A :
1 . Ah : Volume www . seprodstore . com
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