教学内容“球面距离”选自全日制普通高中《数学》第二册第九章第十一节。课堂实录(教师拿着地球仪走进教室,立即引来学生们好奇、疑惑的目光)师:在日常生活中,常常见到飞机总是沿着某一航线飞行,这是为什么呢?下面请同学们思考这样一个问题。 The “spherical distance” of the teaching content is selected from the ninth chapter of the ninth chapter of the second volume of mathematics in full-time regular high school. Classroom Record (The teacher walked into the classroom with a globe and immediately attracted the students’ curiosity and confusion.) Teacher: In everyday life, it is common to see that airplanes always fly along a certain route. Why is this? We think about such a problem.