[Edu-sig] python fun geometry

[roberto]

Recently, i got a lot of fun going through the examples of turtle
geometry in Abelson & Di Sessa original book.
(As already stated in previous thread by me)
Also, i started translating from logo to python all the examples in
the first chapter.
I am over the third paragraph at the moment.
If anyone is interested in receiving the first whole bunch of these
nice codes, just tell me.


Now, i have a geometric question about what the authors write:
in sec 1.1.2 they say that the following logo code:

TO ARCR R DEG
            REPEAT DEG
                  FORWARD R
                  RIGHT 1

produce a circular arc as output, having "DEG" degrees and "R" radius;
and that it's true, actually;
if DEG = 180 the arc is a semicircumference and so on...

But, the "R" in the code is the single step forward the turtle does in
its path so i can't understand how this R can be seen as the radius of
the circular arc.
Any hint is very appreciated.

-- 
roberto