#include#define PI 3.14159class Circle{private:float radius,girth,area;public:Circle(float r=0);//構(gòu)造函數(shù)（以半徑為參數(shù),缺省值為0）Circle(Circle &c);//復(fù)制構(gòu)造函數(shù)void input();//輸入半徑void jisuan();//計(jì)算周長、面積void output();//輸出半徑、周長和面積};Circle::Circle(float r){radius=r;}Circle::Circle(Circle &c){radius=c.radius;}void Circle::input(){coutradius;}void Circle::jisuan(){ girth=2*PI*radius; area=PI*radius*radius;}void Circle::output(){cout