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arXiv · 1502.06628

Other trigonometric proofs of Pythagoras theorem

Nuno Luzia
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Abstract

Only very recently a trigonometric proof of the Pythagoras theorem was given by Zimba \cite{1}, many authors thought this was not possible. In this note we give other trigonometric proofs of Pythagoras theorem by establishing, geometrically, the half-angle formula $\cos\theta=1-2\sin^2 \frac{\theta}{2}$.

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Nuno Luzia. 2015-02-23. Other trigonometric proofs of Pythagoras theorem. https://arxiv.org/abs/1502.06628

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