论文部分内容阅读
求阴影图形的面积,一般方法是通过割补重组、等积变换等手段,把不规则图形转化为可求解的规则图形的组合.而解一些图形构造较为复杂的问题时,用一般的方法会比较麻烦.如果另辟蹊径,通过设元,建立方程组求解,将会简便得多.下面举例说明.例1如图1,已知边长为a的正方形ABCD内接于⊙O,分别以正方形的各边为直径向正方形外作半圆,求四个半圆与⊙O的四条弧围成的四个新月形的面积.
Seeking shaded area, the general method is to cut off the reorganization, isosceles transform and other means, the irregular graphics into a combination of rules and figures can be solved.And some of the more complex graphics solution to the problem, the general method will Is too much trouble .If you find another way, through the set of yuan, the establishment of equations will be much easier .Examples as shown in Figure 1. Example 1 As shown in Figure 1, known as the length of a square ABCD inscribed in the ⊙O, respectively square On each side of the diameter of the square to make a semicircle, seeking four semicircles and ⊙ O surrounded by four arcs surrounded by four crescent-shaped area.