Unix shell script that gets the width, height

Hello,

I need some help to create a Unix shell script that gets the width, height, and depth of a box from
the user and then display a menu of four choices as shown below:
1 - S for The area of the top and bottom surface of the box
2 - A for The surface area of the box
3 - V for The volume of box.
4 - Stop for Exiting the program.
If the user chose any of the first three choices, it will calculate and display the
respective value stated in the menu. Use the case statement for this menu
choice. Your script must allow the user to repeat the tasks unless the user
enters the word "Stop". Include a message to inform the user to enter the
choices from the menu only if the input is not one of the four choices in the
menu.


Any help will be appreciated. Thanks