浙教版初中数学新教科书关于八年级下册的第六章矩形中的第三课时的教材设计和原浙教版教科书一样,没有任何变动,此课时的一个主要内容是定理“直角三角形斜边上的中线等于斜边的一半”的证明.对于这个定理的证明,书本上的证明方法是这样的: The textbook of the junior high school mathematics textbook for the junior high school of the Zhejiang Education Press has no change whatsoever in the sixth lesson of the eighth grade book. The textbook design of the third lesson in the rectangle is the same as that of the original Zhejiang education textbook. One of the major contents of this lesson is theorem "right-angled triangle slanting. The midline on the edge is equal to the half of the hypotenuse. For the proof of this theorem, the proof method in the book is this: