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Other trigonometric proofs of Pythagoras theorem

General Mathematics 2015-02-25 v1

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 cosθ=12sin2θ2\cos\theta=1-2\sin^2 \frac{\theta}{2}.

Keywords

Cite

@article{arxiv.1502.06628,
  title  = {Other trigonometric proofs of Pythagoras theorem},
  author = {Nuno Luzia},
  journal= {arXiv preprint arXiv:1502.06628},
  year   = {2015}
}
R2 v1 2026-06-22T08:36:03.179Z