calculating area

I need a C program that gives 7 choices in the main screen, which is: \r\n \r\n 1- find the area of the circle \r\n 2- find the circumference of the circle \r\n 3- find the area of the square \r\n 4- find the circumference of the square \r\n 5- find the area of the triangle \r\n 6- find the area of the rectangle \r\n 7- Exit\r\n \r\n Then it will ask the user to enter one of these numbers, and if he choose another number it will gives \"please enter a valid number\"\r\n \r\n If he choose 1 for example, new screen will be shown, which will ask the user to enter the radius of the circle and then it will print the area by using the law of circle\' area .. then it will ask the user (Do you want to save the result) if he choose yes then the result will be saved and then it will go back to the main screen , and if he choose no , it will go directly to the main screen, \r\n \r\n The same also for every choice, but the difference will be in the step that will ask about radius or length or height or base or width or what ever we need to find the areas and circumferences \r\n