Using feedback from domain experts

Now, it is time to have a meeting with our domain expert, that is, someone that has an excellent knowledge of 2D geometry. We can use the UML diagram to explain the object-oriented design for the solution. After we explain the different classes that we will use for abstracting the behavior, the domain expert explains to us that there are many shapes that have something in common and that we can generalize the behavior even further. The following six shapes are regular polygons:

• An equilateral triangle (the EquilateralTriangle class) has three sides

• A square (the Square class) has four sides

• A regular pentagon (the RegularPentagon class) has five sides

• A regular hexagon (the RegularHexagon class) has six sides

• A regular octagon (the RegularOctagon class) has eight sides

• A regular decagon (the RegularDecagon class) has ten sides

Regular polygons are polygons that are both equiangular and equilateral. All the sides that compose a regular polygon have the same length...