一道非常容易的几何题 ,由于学生抄题画图时 ,把原图 (图 1 )的字母次序抄错 ,画成如图 2 ,导至师生共同探讨一个新题。现就此新题如何寻求用初中数学知识求解及新题的推广题的一般解法作些探讨。图 1　　　　　　图 2原题 :　如图 1 ,已知梯形ＡＢＣＤ中 ,ＡＢ =1 3 ,ＣＤ =2 A very easy geometry problem, when the students copy the picture, copy the original sequence of the original picture (Figure 1) wrong, and draw it as shown in Figure 2, leading teachers and students to explore a new topic together. We will now discuss some of the general solutions to the problem of how to use the junior mathematics knowledge to solve problems and solve new problems. Fig. 1 Fig. 2 The original problem: As shown in Fig. 1, known as the trapezoid ABCD, AB = 1 3, CD = 2