定义一个圆类(Circle),属性为半径(radius)、圆周长和面积,操作为输入半径并计算周长、面积,输出半径、周长

#include#includeusing namespace std;class Circle{double r,Area,Circumference;public:Circle(double a=0);Circle(Circle &);void SetR(double R);double GetR(){return r;}double GetAreaCircle(){return Area;}...