Introduction - If you have any usage issues, please Google them yourself
1. Declaring a Circle class are: data members Radius (Radius), member function GetArea () to calculate the area of a circle, the constructor Circle (float radius) to initialize and destructors. Create a Circle class object in the main function tests (enter a value for the radius Circle class object, call the object' s GetArea () to find the value of the radius of the area of a circle).