最值问题是中考的一个永恒主题,也是一个难点.解答最值问题不仅要准确理解题意,更要准确找到取得最值的方式,最后才是运用数学知识给出数值.下面结合2016年考题,把最值问题的类型归纳一下.一、把求线段长的最小值转化为求垂线段的长例1(2016·东营)如图1,在Rt△ABC中,∠B=90°,AB=4,BC>AB,点D在BC上,以 The most value problem is a eternal theme in the exam, but also a difficult answer to the most value problem not only to accurately understand the problem, but also to find the most accurate way to get the value, the last is to use mathematics to give the value of the following combination of 2016 exam , The most value of the type of problem summarized.First, the minimum length of the line segment into the vertical line of the long example 1 (2016 · Dongying) in Figure 1, Rt △ ABC, ∠B = 90 °, AB = 4, BC> AB, point D on BC