Calculating The Area Of A Triangle Using Trigonometry - BBC

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  1. Area of triangle
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Area of triangle

Watch this video to learn how to calculate the area of a triangle.

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To be able to calculate the area of a triangle, you need to know two sides and the included angle.

\(Area = \frac{1}{2} ab \sin C\)

Example

Find the area of triangle ABC.

Diagram of triangle with 35° angle and values 3cm and 7cm

\(Area = \frac{1}{2} \times bc \times \sin A\)

\(Area = 0.5 \times 3 \times 7 \times \sin (35^\circ )\)

\(Area = 6.02255...\)

\(Area = 6.02c{m^2}(to\,2\,d.p.)\)

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