反三角恒等式的证明是三角中证明角相等的问题,在这类问题的求证过程中,往往会由于对两角相等的充要条件认识不足及证法单一,而铸成错误。为了让大家对这类问题的多种证法能有个全面的了解,本文拟就反三角恒等式的几种证法,作如下介绍: The proof of the anti-triangular identity is the problem that the angles in the triangle are equal. In the process of verifying such problems, the lack of knowledge of the necessary and sufficient conditions for the two corners and the singleness of the proof are often wrong. In order to allow everyone to have a comprehensive understanding of the various types of evidence for this type of problem, this article proposes several proofs of anti-triangular identity, as follows: