The Square Class

new Square (< double >) -- < square >  

OPERATORS  

< square > .side () -- < double >  

< square > .area () -- < double >  

< square > .perimeter () -- < double >  

< square > .diagonal () -- < double >  

COMMANDS  

< square > .describe ()  

< square > .expand (< double >)  

< square > .shrink (< double >)  

PROBLEM:  

What is the area of the circle which ``circumscribes'' a square of side 11.5?  

SOLUTION:  

double squareSide = 11.5;   Square s = new Square (squareSide);   double diagonalOfSquare = s.diagonal ();   double diameterOfCircle = diagonalOfSquare;   double radius = diameterOfCircle / 2.0;   Circle cc = new Circle (radius);   IO.println (cc.area ());

 

PROBLEM:  

The design of a square flag is as follows:  

• the background is blue
  
• the middle is a white disk of maximal size,  minus the foreground
  
• the foreground is a blue square which inscribes the disk
  

If the flag measures 3 feet on the side,  what is the blue area of the flag?  

The idea...the blue are of the flag = the area of the flag - the area of the disk + the area of the (small) square.  

SOLUTION:  

?   class -- BlueAndWhiteFlagApp   ?   needs -- import blue.shapes.   *;   ?   program       / /Model the flag.           double flagSide = 3.0;           Square flag = new Square (flagSide);       / /Model the disk.           double diskDiamter = flagSide;           double diskRadius = diskDiameter / 2.0;           Circle disk = new Circle (diskRadius);       / /Model the small square.           double helperSquareSide = flagSide / 2.0;           Square helper = new Square (helperSquareSide);           double smallSquareSide = helper.diagonal ();           Square smallSquare = new Square (smallSquareSide);       / /Compute the blue area.           double blueArea = flag.area () - disk.area () +           smallSquare.area ();       / /Display the results.           IO.print (``The blue area is ``);           IO.print (blueArea);           IO.println ();

 

Charles Mingus on Creativity

Definition   IMAGINITIVE CONSTRUCTION is the problem solving strategy of idendtifying a key (essential) object,  not readily apparent in the problem description,  whose creation and manipulation renders the problem solution ``simpler.''