(a) Implement the CircularShape class that was discussed in self-test question 1 above. (b) Add the calculateDiameter method into this class as discussed in self-test question 1d and 1e above. (c)...

(a) Implement the CircularShape class that was discussed in self-test question 1 above. (b) Add the calculateDiameter method into this class as discussed in self-test question 1d and 1e above. (c) Write a program to test out your class. This program should allow the user to enter a value for the radius of the circle, and then display the area, circumference and diameter of this circle on the screen by calling the appropriate methods of the CircularShape class. (d) Modify the tester program above so that once the information has been displayed the user is able to reset the radius of the circle. The area, circumference and diameter of the circle should then be displayed again.