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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____________________ Racket Users list: http://lists.racket-lang.org/users
