This lesson focuses on sphere geometry. It aims to encourage students to solve real science problems in our daily life and explore the unknowns on the sphere. Although some of the ideas in the video are slightly challenging, the overall difficulty of the lesson is suitable for all students above junior level. To follow the lesson, students need to have some basic knowledge about circles, planar geometry and so on. It will take approximately 50 minutes to complete the whole class. During the class, the materials listed here are needed: small globes, pens, paper, scissors, calculators, soft rulers, rubber band, balls with different size, some strings, etc. It is important to present a globe throughout the class to help students visualize the problems. For example, in the Muslim Prayer problem, it is really important to make students understand the geographical location of Mecca and Boston on both the map and the globe.

这堂课是关于球面几何的。它旨在激发学生在解决生活实际问题和探索球面上的未知的兴趣。虽然有一部分知识和问题具有一定的挑战性，但总体而言课程难度适合所有初中生以上的学生。学生需要有一些关于平面几何的圆的基础知识等。整堂课大约需要50分钟来完成。课堂里需要以下材料：小型地球仪，笔，草稿纸，剪刀，计算器，软尺，橡皮筋，不同大小的球，短绳等。地球仪需要一直展示在学生前贯穿整堂课，这样学生更方便直观的理解问题。例如，在穆斯林礼拜问题中，让学生清楚的看到波士顿和麦加在地球仪和地图上分别的地理位置是非常重要的