$\"\"$

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Redraw the diagram.

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$\"\"$

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The area of the triangle is $\"\"$ .

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From the small right angle triangle.

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Trigonometric function : $\"\"$ .

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$\"\"$

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Substitute $\"\"$ in $\"\"$ .

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$\"\"$

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Area of the triangle is $\"\"$ .

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$\"\"$

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Area of the triangle is $\"\"$ .