Re: Lack of geometry

[CJ FINE <cbmvax!uunet!bradford.ac.uk!C.J.Fine>]

Nice try for going at the geometry, but ...
I find several of your proposed lujvo rather flabby - by which I mean
yes, they would do, but they don't sound like the result of careful
thought. One thing that occurs to me is that many of the words have
several meanings in English, and need several different lujvo.

>  
> > triangle        cibjantra [three-angle-shape]
> > rectangle       ganrykurfa [broad-square]
> > rhombus         kurkro [square-bent]
> > polygon         so'irkoitra [many-edge-shape]

Why is a triangle made of angles but a polygon of edges?  Either edge,
angle or line would do, but please use them consistently. There
were suggestions for these in a JL - either 8 or 11. cibli'i, I think.

I find ganrykurfa very impressionistic also - it's equally well a
nalganrykurfa. 'unequal square' would be better, or (for many purposes)
'right-angled quadrilateral' (remember a square is a rectangle)

And 'kurkro' is not bad for rhombus, but surely 'bent-square' is better.
In general, 'equal quadrilateral' is more precise.

>  
> > circle          cukla tarmi     -- cukla is "circular", tarmi is "shape"
>         or 'cuktra' in lujvo form
> > ellipse         ganrycuktra [broad-circular-shape]
> > parabola        selrerkru [thrown-curve]
>         because a parabola is the path of a thrown object
> > hyperbola       bancykemselrerku [beyond-parabola]
>         or make le'avla:  kruvrparabola, kruvrxuperbola.

Same objection for 'ellipse'. 'unequal circle?' 
The metaphor for parabola is the same as the Greek one we use in
English, and is assuredly appropriate for some uses - when talking about
ballistics, for example. But it seems to me that when we are talking
about geometry, it would be preferable to use a geometric
characterisation: make a lujvo for '2nd degree curve', and then
characterise it as 'open'? .iacu'i
(In some contexts it could be a 'parallel-slope ke cone-cut curve'. Do
we have expression for these?)

Hyperbola, similarly, but there the Greek metaphor is less
comprehensible to most people.  'Ellipse', by the way is the same
metaphor: 'falling away', ie falling short of the parabola.

>  
> > axis            jendu??
>         No, that's a physical object (axle); try "selcarna",
>         the rotated-on thing.

Nice catch. Notice that an axis can be to do with symmetry as well as
rotation.

> > diameter        nizganra [quantity-of-wideness]
> > radius          xabykemnizganra [half-diameter]
>         or make le'avla:  cmacnradi

Again, there are two different diameters: 'nizganra' will do for the
diameter of a general closed curve; but I would prefer something more
precise for the diameter of a circle. 'across-measure'? Notice that in
mathematical writing we sometimes use 'diameter' to mean a line across
rather than its measure, and this is different again.

To me, being half the diameter is an incidental property of the radius:
something like 'edge distance' is better.

	co'omi'e kolin