Introduction - If you have any usage issues, please Google them yourself
(1) in two-dimensional space, using the x, y coordinates of a point can be determined determine the center coordinates and the radius of a circle can be determined later. Declaring a Point class, and use this point as a data object of the class member declarations round classes. (2) to design and test a class named Ellipse ellipse whose property is the upper left and lower right corner of bounding rectangle coordinates of two points, and to calculate the area of the ellipse