解三角形问题,主要是处理三角形中的边、角关系.即通过已知的边角关系,确定三角形中未知量和未知关系.数学竞赛中的解三角形问题,常涉及以下知识点.设△ABC的三个角为A,B,C,它们对应的边分别为a,b,c,△ABC的外接圆的半径为R,△ABC的面积为S.1)正弦定理:sinaA=sinbB=sinCC=2R;2) To solve the triangle problem, it mainly deals with the relationship between the edges and corners in the triangle, that is, the unknown quantity and the unknown relationship in the triangle are determined by the known corner relations.The triangle problem in mathematical competition often involves the following knowledge points: △ ABC A, B, C, the corresponding edges are a, b, c, the radius of circumcircle of △ ABC is R, the area of ​​△ ABC is S.1) Sine theorem: sinaA = sinbB = sinCC = 2R; 2)