【教学内容】苏教版四年级下册第75、76页例1、例2及练习十二第l、2题。【教材简析】《认识三角形》这部分内容是在学生直观认识三角形、平行四边形,认识角、垂线和平行线的基础上进行教学的。主要通过观察、操作、比较等具体的活动,帮助学生进一步认识三角形的基本特征,在此基础上掌握三角形对应边上高的画法。【教学目标】1.通过动手操作和观察比较,认识三角形的特点,理解和掌握三角形的定义。2.结合具体情境认识三角 Teaching content】 【Sujiao version of the fourth grade volume 75, 76 Example 1, Example 2 and Practice 12 l, 2 questions. 【Textbook Analysis】 “Understanding Triangle” This part is based on the students intuitive understanding of the triangle, parallelogram, angle of knowledge, vertical and parallel lines based on teaching. Mainly through observation, operation, comparison and other specific activities to help students further understand the basic characteristics of the triangle, on the basis of which to grasp the triangle corresponds to the edge of the high painting. Teaching Objectives 1. Through the hands-on operation and observation and comparison, recognize the characteristics of the triangle, understand and grasp the definition of the triangle. 2. Combination of specific situations to understand the triangle