求阴影部分面积是中考、竞赛试题中经常出现的内容。这类问题题型多样,技巧性强,因而许多同学常感到困难。本文以中考题为例归纳这类问题常用求解策略。一、和差法把阴影部分面积转化为若干个图形面积的和差来解。例1 如图1,设计一个商标图案(图中阴影部分),矩形ABCD中,AB=2BC,且AB= Finding the area of ​​shadows is often the content of the examinations and contests. This type of problem has a variety of questions and skills, so many students often feel difficult. This paper uses the exam questions as an example to summarize the common solution strategies for this type of problem. First, the difference method converts the area of ​​the shadow area into the difference between the area of ​​several patterns to solve. Example 1 As shown in Figure 1, design a logo pattern (shaded part in the figure), rectangle ABCD, AB=2BC, and AB=