Very simple about the problem, just don't know why

Very simple question, just don't know why?
index.php

PHP Code

  
               Calculation                

  
   
    
   Perimeter area Calculation
  
   
        

  
   
    
               Square | |             Triangle | |             Circular                    
  
   
                
  
        

form.class.php

PHP Code

  
  Shape=isset ($_request["id"])?        $_request["id"]: "rect";            } function __tostring () {$form = ';        return $form; } Private Function GetRect () {$input = '
Please enter the width and height of the rectangle
'; $input. = '
Width:
'; $input. = '
Height:
';        return $input; } Private Function Gettriangle () {$input = '
Please enter three sides of the triangle
'; $input. = '
First side:
'; $input. = '
Second side:
'; $input. = '
Third side:
';        return $input; } Private Function Getcircle () {$input = '
Please enter the radius of the circle
'; $input. = '
Radius:
';        return $input; }}?>

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When the point triangle, why output ' no this graph ', where is wrong?

------Solution--------------------
Id=triangle

Case "Triangle":

=====================
Understand??

