A circle in the plane can be described by its center point and
its radius. Class Circle describes objects that are circles in the
plane, and its definition is partially given below.
Some operations on circles are provided. For example, function
area returns the area of a circle. Write the definition
of function area, as it would occur in file circle.cc. Use
approximation 3.1416 for pi.
class Circle
{
public:
Circle(Point center, double radius);
double area();
...
private:
Point myCenter;
double myRadius;
};