Write a Circle class that has the following member variables;

radius: a double

pi: a double with value 3.14159

The class should have the following member functions:

Default Constructor. A default constructor that sets radius to 0.0.

Constructor. Accepts the radius of the circle as an argument.

setRadius. A mutator function for the radius variable.

getRadius. An accessor function for the radius variable.

getArea. Returns the area of the circle, which is calculated as

area = pi * radius * radius

getDiameter. Returns the diameter of the circle, which is calculated as

diameter = radius * 2

getCircumference. Returns the circumference of the circle, which is calculated as

circumference = 2 * pi * radius

Write a program that demonstrates the Circle class by asking the user for the circles radius, creating the Circle object, and then reporting the circle area, diameter, and circumference.

Create and use separate specification and implementation files for the Circle class. Use the include guard (#ifndef/#define/#endif) within your class specification file to prevent multiple class definitions. The member variables radius and pi should be declared private and all methods declared public. Only the accessor method for radius may be declared inline.