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What does the law of cosines reduce to when dealing with a right triangle

User Bamba
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1 Answer

4 votes

Answer:

Pythagorean theorem

Explanation:

We know that for a triangle if we know two sides and the included angle, the third side can be found out using cosine formula


a^2=b^2+c^2-2bc cos A

For a right angle triangle right angled at A this becomes


a^2=b^2+c^2-2bc cos A\\=b^2+c^2-2bc cos 90\\=b^2+c^2-0\\=b^2+c^2

This is nothing but Pythagorean theorem

User Adam Kinney
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