由几何图形求函数解析式,是中考的一个常见题型。这类综合题是以几何图形为背景,通过几何图形性质,将图形中的相关几何量反映为函数关系。理解几何图形的位置变化所引起的相关量的变化,是解这类题的前提,挖掘几何图形的相关量的几何关系,找到其数学表达式是解题的难点和关键。 Finding a function analytical form from a geometric figure is a common question in the examination. This type of comprehensive problem is based on the geometry as a background. Through the nature of the geometry, the relevant geometric quantities in the graph are reflected as functional relationships. Understanding the change of the relevant quantity caused by the position change of the geometric figure is the premise of solving such a problem. It is difficult and key to solve the problem by finding the geometric relationship of the related quantity of the geometric figure and finding its mathematical expression.