Associated Topics || Dr. Math Home || Search Dr. Math

### Pyramid Corners

```
Date: 05/01/2001 at 18:07:01
From: Mrs. Beauchamp's class
Subject: Pyramids

How many corners does a pyramid have? We have found that the point is
called a vertex, but is this considered a corner?
```

```
Date: 05/06/2001 at 14:01:17
From: Doctor Douglas
Subject: Re: Pyramids

Hi everyone,

A square pyramid (one that has a square base) has five vertices. If
the pyramid has a triangular base, then it is called a "tetrahedron"
and has only four vertices.

Mathematicians prefer the word "vertex" because it is more *precise*
than the word "corner." For example, we often think that a room has
four corners because we are referring to the four vertical edges
rather than the eight vertices. If this were the definition of
"corner" that we are supposed to use for the square pyramid, then it
would have four corners (and five vertices).

I hope this helps. Please write back if you'd like to discuss this
some more, or if you have other questions.

- Doctor Douglas, The Math Forum
http://mathforum.org/dr.math/
```
Associated Topics:
Elementary Definitions
Elementary Geometry
Elementary Polyhedra
Middle School Definitions
Middle School Geometry
Middle School Polyhedra

Search the Dr. Math Library:

 Find items containing (put spaces between keywords):   Click only once for faster results: [ Choose "whole words" when searching for a word like age.] all keywords, in any order at least one, that exact phrase parts of words whole words

Submit your own question to Dr. Math
Math Forum Home || Math Library || Quick Reference || Math Forum Search