TODO: Test 2 - Create the GetArea() member method
 * ==================================================
 * Inside the Circle class within your Shape.cpp file,
 * create a new member method called GetArea(). This
 * method should return the area of the current Circle
 * object represented as a float.
 *
 * Once the method has been created, initialize and return a
 * Circle-type object using the given x, y, and radius
 * parameters.

Tips:
 * - You will not be able to complete Test 2 until Test 1
 *   is fully completed.
 * - C++ does not contain a constant variable defining the
 *   value for Pi. As a result, you should use a float value
 *  of 3.14f.