编程计算图形的面积。（程序可计算长方形、正方形和圆形的面积，运行时提示用户选择图形的类型，然后按要求输入相关数据计算面积。,Calculate the area of graphics programming. (Program calculate rectangular, square and round the area, run-time prompts the user to select the type of graph, and then asked to enter the re