《凸多边形内角和定理》教学谈王嘉锦多边形内角和定理的重点是多边形的内角和定理的证明，我在实践中运用“主体式”教学法，取得了比较理想的教学效果．首先师生共同复习三角形、四边形的有关概念及三角形内角和定理，并在黑板上作出多边形Ａ１Ａ２Ａ３…Ａｎ－１Ａｎ（... The teaching of “Interior Convex Polygon Angles and Theorems” focuses on Wang Jiajin’s polygon interior angle and theorem. The emphasis is on the polygon interior angle and the proof of the theorem. In practice, I use the “subjective” pedagogy and achieved a relatively satisfactory teaching effect. First of all, teachers and students jointly review the concepts related to triangles, quadrilaterals, triangle inner angles and theorems, and make polygons A1A2A3... An-1An (...