Create the classes RightTriangle and Rectangle, each of which is derived from the abstract class ShapeBase in Listing 8.19. Then derive a class Square

Question

from the class Rectangle. Each of these three derived classes will have two additional methods to calculate area and circumference, as well as the inherited methods. Do not forget to override the method drawHere. Give your classes a reasonable complement of constructors and accessor methods. The Square class should include only one dimension, the side, and should automatically set the height and width to the length of the side. You can use dimensions in terms of the character width and line spacing even though they are undoubtedly unequal, so a square will not look square (just as a Rectangle object, as discussed in this chapter, won’t look square.) Write a driver program that tests all your methods.

This project is most easily written by modifying the programs in the text. Base RightTriangle.java on Triangle.java (Listing 8.14), Rectangle.java on Rectangle.java (Listing 8.13), and MoreGraphicsDemo.java on TreeDemo.java (Listing 8.15). Square.java is derived from Rectangle, so it is just a matter of using the parent’s methods with both height and width set to the length of the side of the square. Note that special attention is required to draw the correct figures when the base, width, or height values are either 0 or 1.

Answer 1

See the code in RightTriangle.java, Rectangle.java, SquarePr7,java, and MoreGraphicsDemo.java.