9.8

Author: Sarah Akinkunmi

src/ChapterNine/QuadrilateralInheritanceHierarchy/Parallelogram.java

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+package ChapterNine.QuadrilateralInheritanceHierarchy;
+
+public class Parallelogram extends Quadrilateral{
+    private int height;
+
+    public Parallelogram(Point firstPoint, Point secondPoint, Point thirdPoint, Point fourthPoint, int height) {
+        super(firstPoint, secondPoint, thirdPoint, fourthPoint);
+        this.height = height;
+    }
+
+    public int getHeight() {
+        return height;
+    }
+
+    public void setHeight(int height) {
+        if(height < 0.0) {
+            throw new IllegalArgumentException("Enter a height greater than 0!");
+        }
+        this.height = height;
+    }
+
+    public double getArea(){
+        return (getFourthPoint().getXCoordinate() - getThirdPoint().getXCoordinate() * height);
+    }
+
+    @Override
+    public String toString() {
+        return String.format("%s%.4f", "The area of a rectangle is", getArea());
+    }
+}

src/ChapterNine/QuadrilateralInheritanceHierarchy/Point.java

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+package ChapterNine.QuadrilateralInheritanceHierarchy;
+
+public class Point {
+    private int xCoordinate;
+    private int yCoordinate;
+
+    public Point(int xCoordinate, int yCoordinate) {
+        this.xCoordinate = xCoordinate;
+        this.yCoordinate = yCoordinate;
+    }
+
+    public int getXCoordinate() {
+        return xCoordinate;
+    }
+
+    public void setXCoordinate(int xCoordinate) {
+        this.xCoordinate = xCoordinate;
+    }
+
+    public int getYCoordinate() {
+        return yCoordinate;
+    }
+
+    public void setYCoordinate(int yCoordinate) {
+        this.yCoordinate = yCoordinate;
+    }
+}

src/ChapterNine/QuadrilateralInheritanceHierarchy/Quadrilateral.java

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+/*
+9.8 (Quadrilateral Inheritance Hierarchy) Write an inheritance hierarchy for classes Quadrilateral,
+Trapezoid, Parallelogram, Rectangle and Square. Use Quadrilateral as the superclass of the hierarchy.
+Create and use a Point class to represent the points in each shape. Make the hierarchy as deep (i.e., as many
+levels) as possible. Specify the instance variables and methods for each class. The private instance variables
+of Quadrilateral should be the x-y coordinate pairs for the four endpoints of the Quadrilateral.
+Write a program that instantiates objects of your classes and outputs each object’s area (except Quadrilateral).
+ */
+
+package ChapterNine.QuadrilateralInheritanceHierarchy;
+
+public class Quadrilateral {
+    private Point firstPoint;
+    private Point secondPoint;
+    private Point thirdPoint;
+    private Point fourthPoint;
+
+    public Quadrilateral() {}
+
+    public Quadrilateral(Point firstPoint, Point secondPoint, Point thirdPoint, Point fourthPoint) {
+        this.firstPoint = firstPoint;
+        this.secondPoint = secondPoint;
+        this.thirdPoint = thirdPoint;
+        this.fourthPoint = fourthPoint;
+    }
+
+    public Point getFirstPoint() {
+        return firstPoint;
+    }
+
+    public void setFirstPoint(Point firstPoint) {
+        this.firstPoint = firstPoint;
+    }
+
+    public Point getSecondPoint() {
+        return secondPoint;
+    }
+
+    public void setSecondPoint(Point secondPoint) {
+        this.secondPoint = secondPoint;
+    }
+
+    public Point getThirdPoint() {
+        return thirdPoint;
+    }
+
+    public void setThirdPoint(Point thirdPoint) {
+        this.thirdPoint = thirdPoint;
+    }
+
+    public Point getFourthPoint() {
+        return fourthPoint;
+    }
+
+    public void setFourthPoint(Point fourthPoint) {
+        this.fourthPoint = fourthPoint;
+    }
+}

src/ChapterNine/QuadrilateralInheritanceHierarchy/Rectangle.java

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+package ChapterNine.QuadrilateralInheritanceHierarchy;
+
+public class Rectangle extends Quadrilateral{
+    public Rectangle(Point firstPoint, Point secondPoint, Point thirdPoint, Point fourthPoint) {
+        super(firstPoint, secondPoint, thirdPoint, fourthPoint);
+    }
+
+    public double getArea(){
+        return (getSecondPoint().getXCoordinate() - getFirstPoint().getXCoordinate()) * (getThirdPoint().getXCoordinate() - getSecondPoint().getXCoordinate());
+    }
+
+    @Override
+    public String toString() {
+        return String.format("%s%.4f", "The area of a rectangle is", getArea());
+    }
+}

src/ChapterNine/QuadrilateralInheritanceHierarchy/Square.java

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+package ChapterNine.QuadrilateralInheritanceHierarchy;
+
+public class Square extends Quadrilateral{
+    public Square() {}
+
+    public Square(Point firstPoint, Point secondPoint, Point thirdPoint, Point fourthPoint) {
+        super(firstPoint, secondPoint, thirdPoint, fourthPoint);
+    }
+
+    public double getArea() {
+        return Math.pow((getSecondPoint().getXCoordinate()) - (getFirstPoint().getXCoordinate()), 2);
+    }
+
+    @Override
+    public String toString() {
+        return String.format("%s%.4f", "The area of a square is", getArea());
+    }
+}

src/ChapterNine/QuadrilateralInheritanceHierarchy/Trapezoid.java

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+package ChapterNine.QuadrilateralInheritanceHierarchy;
+
+public class Trapezoid extends Quadrilateral{
+    private int height;
+
+    public Trapezoid(Point firstPoint, Point secondPoint, Point thirdPoint, Point fourthPoint, int height) {
+        super(firstPoint, secondPoint, thirdPoint, fourthPoint);
+        this.height = height;
+    }
+
+    public int getHeight() {
+        return height;
+    }
+
+    public void setHeight(int height) {
+        if(height < 0.0) {
+            throw new IllegalArgumentException("Enter a height greater than 0!");
+        }
+        this.height = height;
+    }
+
+    public double getArea() {
+        return (0.5 * ((getSecondPoint().getXCoordinate()) - (getFirstPoint().getXCoordinate())) + (getFourthPoint().getXCoordinate() - getThirdPoint().getXCoordinate())) * height;
+    }
+
+    @Override
+    public String toString() {
+        return String.format("%s%.4f", "The area of a trapezoid is", getArea());
+    }
+}