如何用“圆”的基础知识解决实际问题

• 作 者: 丁桂芬
• 出 处: 山西教育(中考)
• 发表日期: 2005年12期
• 关键词: 弦心距 辅助线 数学能力 弦长 折痕 圆相 旋转不变性 轴对称图形 做一做 理得

圆是现实世界中常见的图形,是初中几何的最后一章,从整个初中几何的学习来看,它属于“提高阶段”.在知识方面,不仅需要学好本章的知识,而且还要能综合运用前面学过的知识;在数学能力方面,不仅要掌握好以前学习过的折叠、平移、旋转、推理证明等方法,还要能运用这些知识和方法来

Circle is a common figure in the real world, and it is the last chapter of junior high school geometry. From the perspective of the learning of the entire junior high school geometry, it belongs to the “improvement phase.” In terms of knowledge, it is not only necessary to learn the knowledge of this chapter, but also to use it comprehensively. In terms of mathematics ability, we must not only master the methods of folding, translation, rotation, proof of reasoning, etc. that we have learned in the past, but also use these knowledge and methods.