Write a program that asks the user to select a shape from a menu (1. Circle; 2. Triangle; 3. Rectangle;) and then calculates the area of that shape using user inputs. Use a switch case structure to implement the menu. If the user tries to select an option that isn't on the menu or tries to enter negative values for the dimensions of the shape, print an appropriate error message, and keep asking for valid inputs. Use while to achieve this function. Create a function named as int positive checker(double num), taking an integer as the input and return whether the double number is positive or not. Use this function to test whether the users' inputs for the parameters of the shapes are invalid or not. Use 3.14 for pi. Name your program file Hw3 ql code.c. Example Hints and Inputs: (purple texts are what the program should print on the screen to instruct the users, the black texts are what the users type in) Select the shape you want to calculate the area of 1 Circle 2.Triang 3.Rectangle Illegal input! Please reinput! Please input the radius of the circle: -1 Illegal input! Please reinput Please input the radius of the circle: 1 Example Outputs: The area of the circle is: 3.140000 Example Hints and Inputs: (purple texts are what the program should print on the screen to instruct the users, the black texts are what the users type in)