在高三复习中遇到一道题 :棱长都相等的一个正四面体和一个正八面体 ,把它们拼起来 ,使一个面重合 ,所得的多面体有个面 .答案是 7个 ,学生不理解 ,拿着题来让我帮忙 .相对简单的背景 ,并不复杂的关系不容易引起人的重视 ,然而几遍讲解下来 ,看着学生将信将疑的目光 ,连我自己 In the third year of review, I encountered a question: a regular tetrahedron and an octahedron with equal length and length, and they were put together to make one face coincide. The resulting polyhedron had a face. The answer was seven. Students did not understand it. Let me help you with the subject. Relatively simple background, uncomplicated relationship is not easy to cause people’s attention, but explained it several times, watching the students look at the letter, even my own