Create a new class.

This class will store the coordinates of the four corners of the rectangle.
The constructor must call a control method that receives the four coordinates and check that they are located in the first quadrant (ie, that both the x and y are positive numbers) and that no x or y coordinate is greater than 20.0. The control method also controls the four coordinates really form a rectangle (the return value is preferably bool).
Create methods to calculate the length, width, perimeter and area. Then test the class by creating objects from it and read / print out its characteristics.