一个小的MVC程序。根据输入半径的大小，自动生成圆的面积和周长。-A small MVC program. Radius based on the input size, automatically generated area and circumference of a circle.

求圆形，矩形，三角形的周长和面积，运用到继承的知识-Order to round, rectangular, triangular perimeter and area, apply to the inheritance of knowledge

C++类运用。几何体。 计算圆与圆外接矩形，矩形外接圆。圆外切三角形四个图形的面积。周长。对角线-C++ classes to use. Geometry. Calculated circle and the circle bounding rectangle, rectangle circle. Cut four triangles outside circle graph area. Circumference. Diagonal

实现小学生多边形面积和周长问题的自动出题，自动校验答案，打分存入文件等简单功能，使用了简单的C++指针，继承与派生，多态，文件流等，是一道综合性很强的题目-Using the simple C++ pointer, inheritance and derived, polymorphism, file flow, is a comprehensive strong Of the title