[racket] Can't create circles

See margin remark right next to the expression below: 

(require 2htdp/image)
specifies that you wish to add the "image" library. Alternatively, use the “Language” drop-down menu, choose “Add Teachpack ...” and pick "image".

-- Matthias


On Aug 26, 2012, at 9:14 PM, Geoffrey Boom wrote:

> I'm learning how to use the Racket program, I'm still at the prologue
> of the Second edition of how to design programs. When I type in:
> 
> 
> 
> (* (image-width )
>   (image-height ))
> 
> 
> or
> 
> 
> (circle 10 "solid" "red")
> 
> 
> or
> 
> 
> 
> (rectangle 30 20 "outline" "blue")
> 
> 
> 
> I get the error message:
> 
> 
> image-width: this function is not defined
> circle: this function is not defined
> rectangle: this function is not defined
> 
> 
> I don't know what to do,
> Thanks in advance,
> Geoff.
> ____________________
>  Racket Users list:
>  http://lists.racket-lang.org/users

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