PlanetMath (more info)
 Math for the people, by the people. Sponsor PlanetMath
Encyclopedia | Requests | Forums | Docs | Wiki | Random | RSS  
Login
create new user
name:
pass:
forget your password?
Main Menu
Viewing Version 9 of 'equilateral triangle'
[ view 'equilateral triangle' | back to history ]

Title of object: equilateral triangle
Canonical Name: EquilateralTriangle
Type: Definition

Created on: 2001-10-06 17:57:14
Modified on: 2007-06-05 23:11:55

Creator: Mathprof
Modifier: Mathprof
Author: Mathprof
Author: matte
Author: drini

Classification: msc:51-00
Keywords: Triangle

Revision comment (for changes between this and next version):

Changes for correction #12373 ('Ambiguity').

Preamble:

\usepackage{amssymb}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{graphicx}
\usepackage{xypic}
Content:

An \emph{equilateral triangle} is one for which any two sides are congruent.

.


\begin{center}
\includegraphics{equilat}
\end{center}

The following statements hold in Euclidean geometry for an equilateral triangle.

\begin{itemize}
\item
It is a regular polygon.
\item
The triangle is determined by specifying one side.
\item
The bisector of any angle coincides with the height, the median and the perpendicular bisector of the \PMlinkescapetext{opposite side}.
\item
If $r$ is the length of the side, then the height is equal to $\displaystyle \frac{r\sqrt{3}}{2}$.
\item
If $r$ is the length of the side, then the area is equal to $\displaystyle \frac{r^2\sqrt{3}}{4}$.
\end{itemize}