using inheritance write the program for fallowing ?

Question

Hi

This is my thing i have to do ..

Build a inheritance hierarchy for classes Quadrilateral, Trapezoid, Parallelogram, Rectangle and Square. Use Quadrilateral as the base class 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, properties, 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).

Can anyone help it out ..

I am totally went wrong when i read this "The private instance variables of Quadrilateral should be the x-y coordinate pairs for the four endpoints of the Quadrilateral"

So help me

Cheers

TY

Vulpes · Answer

Although my previous post works I wasn't completely happy with it because whilst Rectangle and Square inherit from Parallelogram they don't actually add or modify anything which ideally they should do in an inheritance hierarchy. Here's an improved version which adds constructor overloads to the Rectangle and Square classes to distinguish them from Parallelogram. Notice that Square now inherits from Rectangle rather than directly from Parallelogram. The results are the same as before: using System; public class Point { private double _x _y; public double X { get {return _x;} } public double Y { get {return _y;} } public Point(double x double y) { _x = x; _y = y; } public override string ToString() { return String.Format(({0}{1}) _x _y); } } public class Quadrilateral { private Point _p1 _p2 _p3 _p4; public Point P1 { get {return _p1;} } public Point P2 { get {return _p2;} } public Point P3 { get {return _p3;} } public Point P4 { get {return _p4;} } public Quadrilateral(Point p1 Point p2 Point p3 Point p4) { _p1 = p1; _p2 = p2; _p3 = p3; _p4 = p4; } public override string ToString() { return String.Join(  new object[]{_p1 _p2 _p3 _p4}); } } public class Trapezoid : Quadrilateral { private double _height; public double Height { get {return _height;} } public Trapezoid(Point p1 Point p2 Point p3 Point p4) : base(p1 p2 p3 p4) { if (p1.Y == p2.Y) { _height = p2.Y - p3.Y; } else { _height = p1.Y - p2.Y; } _height = Math.Abs(_height); } public double Area { get { double sumSides; if (P1.Y == P2.Y) { sumSides = Math.Abs(P1.X - P2.X) + Math.Abs(P3.X - P4.X); } else { sumSides = Math.Abs(P2.X - P3.X) + Math.Abs(P4.X - P1.X); } return sumSides * _height / 2.0; } } } public class Parallelogram : Trapezoid { private double _width; public double Width { get {return _width;} } public Parallelogram(Point p1 Point p2 Point p3 Point p4) : base(p1 p2 p3 p4) { if (p1.Y == p2.Y) { _width = p1.X - p2.X; } else { _width = p2.X - p3.X; } _width = Math.Abs(_width); } } public class Rectangle : Parallelogram { public Rectangle(Point p1 Point p2 Point p3 Point p4) : base(p1 p2 p3 p4) { } public Rectangle(Point position double width double height) : base(position new Point(position.X + width position.Y) new Point(position.X position.Y + height) new Point(position.X + width position.Y + height)) { } } public class Square : Rectangle { public Square(Point p1 Point p2 Point p3 Point p4) : base(p1 p2 p3 p4) { } public Square(Point position double sideLength): base(position sideLength sideLength) { } } class Test { static void Main() { Point p1 = new Point(5 1); Point p2 = new Point(10 1); Point p3 = new Point(1 4); Point p4 = new Point(8 6); Point p5 = new Point(0 5); Point p6 = new Point(15 5); Point p7 = new Point(7 4); Point p8 = new Point(12 4); Point p9 = new Point(5 3); Point p10 = new Point(10 3); Point p11 = new Point(5 6); Point p12 = new Point(10 6); Quadrilateral q = new Quadrilateral(p1 p2 p3 p4); Console.WriteLine(Created quadrilateral with vertices at {0} q); Trapezoid t = new Trapezoid(p1 p2 p5 p6); Console.WriteLine(The area of the trapezoid with vertices at {0} is {1} t t.Area); Parallelogram p = new Parallelogram(p1 p2 p7 p8); Console.WriteLine(The area of the parallelogram with vertices at {0} is {1} p p.Area); Rectangle r = new Rectangle(p1 5 2); Console.WriteLine(The area of the rectangle with vertices at {0} is {1} r r.Area); Square s = new Square(p1 5); Console.WriteLine(The area of the square with vertices at {0} is {1} s s.Area); Console.ReadKey(); } }

Vulpes · Answer

The choice of points was entirely off the top of my head. Square and rectangle are easy as you know that opposite sides are parallel to each other and that all sides are equal in the case of a square. For parallelogram it's just a matter of offsetting the points for the top (or bottom) vertices of a rectangle so the whole figure is slanted to one side. In the case of a trapezoid two sides are parallel to each other so I just had to choose the points for the other two sides so they wouldn't be parallel. Finally for quadrilateral I just chose four points so that there would be no parallel sides. I don't know of any online tool which can generate such points though the Wikipedia articles for these geometric figures may contain some examples.

Vulpes · Answer

Try this: using System; public class Point { private double _x _y; public double X { get {return _x;} } public double Y { get {return _y;} } public Point(double x double y) { _x = x; _y = y; } public override string ToString() { return String.Format(({0}{1}) _x _y); } } public class Quadrilateral { private Point _p1 _p2 _p3 _p4; public Point P1 { get {return _p1;} } public Point P2 { get {return _p2;} } public Point P3 { get {return _p3;} } public Point P4 { get {return _p4;} } public Quadrilateral(Point p1 Point p2 Point p3 Point p4) { _p1 = p1; _p2 = p2; _p3 = p3; _p4 = p4; } public override string ToString() { return String.Join(  new object[]{_p1 _p2 _p3 _p4}); } } public class Trapezoid : Quadrilateral { private double _height; public double Height { get {return _height;} } public Trapezoid(Point p1 Point p2 Point p3 Point p4) : base(p1 p2 p3 p4) { if (p1.Y == p2.Y) { _height = p2.Y - p3.Y; } else { _height = p1.Y - p2.Y; } _height = Math.Abs(_height); } public double Area { get { double sumSides; if (P1.Y == P2.Y) { sumSides = Math.Abs(P1.X - P2.X) + Math.Abs(P3.X - P4.X); } else { sumSides = Math.Abs(P2.X - P3.X) + Math.Abs(P4.X - P1.X); } return sumSides * _height / 2.0; } } } public class Parallelogram : Trapezoid { private double _width; public double Width { get {return _width;} } public Parallelogram(Point p1 Point p2 Point p3 Point p4) : base(p1 p2 p3 p4) { if (p1.Y == p2.Y) { _width = p1.X - p2.X; } else { _width = p2.X - p3.X; } _width = Math.Abs(_width); } } public class Rectangle : Parallelogram { public Rectangle(Point p1 Point p2 Point p3 Point p4) : base(p1 p2 p3 p4) { } } public class Square : Parallelogram { public Square(Point p1 Point p2 Point p3 Point p4) : base(p1 p2 p3 p4) { } } class Test { static void Main() { Point p1 = new Point(5 1); Point p2 = new Point(10 1); Point p3 = new Point(1 4); Point p4 = new Point(8 6); Point p5 = new Point(0 5); Point p6 = new Point(15 5); Point p7 = new Point(7 4); Point p8 = new Point(12 4); Point p9 = new Point(5 3); Point p10 = new Point(10 3); Point p11 = new Point(5 6); Point p12 = new Point(10 6); Quadrilateral q = new Quadrilateral(p1 p2 p3 p4); Console.WriteLine(Created quadrilateral with vertices at {0} q); Trapezoid t = new Trapezoid(p1 p2 p5 p6); Console.WriteLine(The area of the trapezoid with vertices at {0} is {1} t t.Area); Parallelogram p = new Parallelogram(p1 p2 p7 p8); Console.WriteLine(The area of the parallelogram with vertices at {0} is {1} p p.Area); Rectangle r = new Rectangle(p1 p2 p9 p10); Console.WriteLine(The area of the rectangle with vertices at {0} is {1} r r.Area); Square s = new Square(p1 p2 p11 p12); Console.WriteLine(The area of the square with vertices at {0} is {1} s s.Area); Console.ReadKey(); } }

Vulpes · Answer

X and Y are the names of the properties. They appeared in the above program in expressions such as P1.X and P2.Y.

Maha · Answer

What is X and Y public double X { get {return _x;} } public double Y { get {return _y;} }

Vulpes · Answer

Those are read-only properties (i.e. get only) which get the value of the fields _x and _y. This effectively makes the Point class immutable - one you've created an instance you can't change it.

Maha · Answer

Whether it is possible to explain the function of the followings in the program? public double X { get {return _x;} } public double Y { get {return _y;} }

Maha · Answer

Thanks

Maha · Answer

Vulpes how did you decide appropriate points for Quadrilateral Trapezoid Parallelogram Rectangle Square I know only traditional way to use to decide those appropriate points. Is there any website tool available to make work easy?