The Math Forum

Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.

Math Forum » Discussions » Math Topics » geometry.pre-college

Topic: Trapezoid definition
Replies: 26   Last Post: Oct 7, 2004 11:51 PM

Advanced Search

Back to Topic List Back to Topic List Jump to Tree View Jump to Tree View   Messages: [ Previous | Next ]
Lee Rudolph

Posts: 3,143
Registered: 12/3/04
Re: Trapezoid definition
Posted: Aug 9, 2000 2:19 PM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

Mary Krimmel asks:

>Now: it seems undisputable that the concept of counting numbers precedes
>the concepts of rationals, integers, and so on both in individual
>development and in social/mathematical history, but what about the
>geometric figures?
>I think that a circle comes first (and I see it not as a disk although
>that's what's usually presented to toddlers being prematurely tutored in
>"shapes") both for an individual and society? Then what?

This is a fascinating question. I hope someone has authoritative
information on it; I certainly don't! Anecdotally, I can mention
that I've been in quite a few caves in Spain (Tito Bustillo, Altamira,
...) and France (Lascaux--well, the replica thereof--,...), with wall
decorations from the Paleolithic era, and I've kept my eye out (and
occasionally asked guides) for evidence of the beginings of mathematics.
Groups of dots seem to be it, in that era, and those very rarely
(and ambiguously); no circles, arcs, disks, no straight lines or
broken lines or polygons. At least, I don't remember noting them;
I'd like to be corrected.

Jump forward to the Neolithic, though, as for instance in Valcamonica,
Italy, , and we find
engravings (not in caves! on huge, glacier-scrubbed flat rocks
outside, where they were lost to sight until about 20 years ago)
of spirals (circa 5500 years Before Present), see ...
in another 1000 years, triangles (not abstract; images of
weapons) appear there, .
But I suppose they're everywhere by then.

Lee Rudolph

Point your RSS reader here for a feed of the latest messages in this topic.

[Privacy Policy] [Terms of Use]

© The Math Forum at NCTM 1994-2017. All Rights Reserved.