Introduction - If you have any usage issues, please Google them yourself
Function overloading application requirements: 1. Defined function 1. Circle (input radius), 2. Rectangles (Enter the length and width), 3. Square (input side), 4. Fan-shaped area (input central angle and radius) ② to the user prompt 1. Round 2. rectangles, 3. square, 4. fan of the area, 0. exit ③ According to the function prompts the user to select parameters ④ graphics area of computing and display.