> Learning the relations between different geometric figures is
> useful.

I think it can be see best from similarity in the text.

> > Old: "A rectangle has four sides and L-shaped corners."
> > New: "A rectangle has four sides and four right angles."
> >
> > This is getting advanced. Classifying angles is a
> > part of geometry, in the 9th or 10th year of school.
> 
> AFAICS, it's part of grade 7 in the US.
> 
> But surely the kids have heard the term �straight angle� before?
> (If not, they can learn it from Tux Paint! :) )

That's also 9th or 10th year and... it means 180 degrees!

> > Old: "A rhombus has four equal sides."
> > New: "A rhombus has four equal sides, and opposite sides are
> > parallel."
> >
> > The first part is enough to define a rhombus. The second
> > part requires geometry.
> 
> No, the first part defines a quadrangle. The second part is
> needed.

four EQUAL sides

That is a rhombus. Well, there's a degenerate "shape"
with lines crossing, but maybe that is a rhombus too.

> But the rhombus may as well be removed. It's just a rotated
> square, and Tux Paint supports rotating.

No. This was the major error that convinced me to touch
that file in the first place. A rhombus with angles of
30 degrees and 60 degrees is not a rotated square.


_______________________________________________
Tuxpaint-dev mailing list
[email protected]
http://tux4kids.net/mailman/listinfo/tuxpaint-dev

Reply via email to