若有以下程序: #include <iostream> using namespace std; #define PI 3.14 class Point private: int x,y; public: Point(int a,int B) x=a; y=b; int getx() return x; int gety() reurn y; ; class Circle: public Point private: int r; public: Circle(int a,int b.int C) :Point(a,B) r=c; int getr() return r; double area() return PI*r*r; ; int main() Circle cl(5,7,10); cout<<c 1 .area()<<end1; return 0; 程序执行后的输出结果是