论文部分内容阅读
一、知识要点回顾 三角形中的边角关系,是研究几何中许多边角问题的基础,在初二几何里,边角关系主要有以下内容: 1.边的关系 (1)三角形两边的和大于第三边,两边的差小于第三边.(三角形边的关系定理及其推论) (2)直角三角形两直角边a、b的平方和等于斜边c的平方.即a2+b2=c2.(勾股定理) 2.角的关系 (1)三角形三个内角的和等于180°.(三角形内角
First, knowledge points Reviewing the corner relations in triangles is the basis for studying many corner problems in geometry. In the second geometry, the corner relations mainly include the following: 1. The relationship of edges (1) The sum of the sides of the triangle is greater than On the third side, the difference between the two sides is smaller than the third side. (Triangle-side relation theorem and its inference) (2) The sum of the squares of the right-angled triangle sides a and b is equal to the square of the hypotenuse c. That is, a2+b2=c2. (Pythagorean Theorem) 2. Relation of angles (1) The sum of the three inner angles of a triangle is equal to 180°.