Dimensions

Date: 08/30/2001 at 20:52:22
From: Emily 
Subject: Dimension

What are 1-dimensional, 2-dimensional, and 3-dimensional? What's the 
difference?

Date: 08/30/2001 at 23:02:40
From: Doctor Peterson
Subject: Re: Dimension

Hi, Emily.

Essentially, an N-dimensional object is one that requires N numbers to 
describe a location in it. 

A line is 1-dimensional, since one number, the distance from zero, 
tells you where you are. 

A plane is 2-dimensional, since you need x and y to locate a point. 

A circle (the curve itself, not the interior of it) is a 1-dimensional 
object in a 2-dimensional space, since although it takes 2 numbers to 
identify where in the plane a point on the circle is, only one number 
(the angle from a starting position) tells you where you are as long 
as you know you are on the circle.

For 3 dimensions, here is a discussion I found in our archives:

   Is a Sphere 2-D or 3-D?
   http://mathforum.org/dr.math/problems/janice.8.8.96.html   

- Doctor Peterson, The Math Forum
  http://mathforum.org/dr.math/