23 Maths -- Trigonometry

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The Area of Triangle

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The area of triangle ABC with the given measurement as shown in fig is '∆'. 's' is the semi-perimeter of the triangle such that 2s=(

).
We know, area of triangle is given by;

From Half-angle formula, we have,

1^st Proof:

2^nd Proof:
We have,

3^rd Proof:

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