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面积问题是小学数学竞赛与小升初一个重点问题,要求解答求平面图形的周长与面积,立体图形的表面积和体积等问题。除了要掌握图形的特征和计算公式外,还要理解这些公式的推导过程,并且能灵活运用以下方法:1.平移法。就是把图形中的一部分(线段的长度、某些部分的面积或体积)通过平移、旋转、翻折等移动位置,从而构成规则的图形,运用公式解决问题。2.割补法。把要求的部分通过分割与弥补,转化为规则图形来解决问题,通常可以把比较的几个部分同时加上或减掉相同的部分。3.变形法。立体图形没入水中和取出水面,可以利用水的体积不变来找到上升或
Area problem is the primary school mathematics competition and Xiao Sheng a key issue in the beginning, asked to find the circumference and area of the plane graphics, three-dimensional graphics of the surface area and volume issues. In addition to grasping the characteristics of the graphics and formulas, but also to understand the derivation of these formulas, and can flexibly use the following methods: 1 translation method. That is, a part of the graph (the length of the segment, the area or the volume of some parts) is translated into a regular pattern through translation, rotation and folding, and the formula is used to solve the problem. 2 cut law. To solve the problem by dividing and compensating the required part into a regular figure, it is usually possible to add or subtract the same part of the comparison at the same time. 3 deformation method. Three-dimensional graphics into the water and remove the surface, you can use the same volume of water to find the rise or