|
|
|
Revision difference : length |
| Version 4 |
Version 3 |
| The \emph{length} of a line segment is the distance between its startpoint and its endpoint. Length may be measured in meters, yards, abstract units, etc. For example, if in the following diagram |
The \emph{length} of a line segment is the distance between its startpoint and its endpoint. Length may be measured in meters, yards, abstract units, etc. For example, if in the following diagram |
|
|
| \begin{center} |
\begin{center} |
| \begin{pspicture}(-1,-0.3)(5,0.3) |
\begin{pspicture}(-1,-0.3)(5,0.3) |
| \psline{<->}(-1,0)(5,0) |
\psline{<->}(-1,0)(5,0) |
| \psdots(0,0)(1,0)(3,0)(3.2,0)(4,0) |
\psdots(0,0)(1,0)(3,0)(3.2,0)(4,0) |
|
\rput[a](0,-0.3){0}
|
\rput[a](0,-1){0}
|
|
\rput[a](1,-0.3){1}
|
\rput[a](1,-1){1}
|
|
\rput[a](3,-0.3){3}
|
\rput[a](2,-1){3}
|
|
\rput[a](3.5,-0.3){3.2}
|
\rput[a](3.5,-1){3.2}
|
|
\rput[a](4,-0.3){4}
|
\rput[a](4,-1){4}
|
| \rput[b](0,0.2){$A$} |
\rput[b](0,0.2){$A$} |
| \rput[b](1,0.2){$B$} |
\rput[b](1,0.2){$B$} |
| \rput[b](2.8,0.2){$C$} |
\rput[b](2.8,0.2){$C$} |
| \rput[b](3.2,0.2){$D$} |
\rput[b](3.2,0.2){$D$} |
| \rput[b](4,0.2){$E$} |
\rput[b](4,0.2){$E$} |
| \rput[r](-1,0){.} |
\rput[r](-1,0){.} |
| \rput[l](5,0){.} |
\rput[l](5,0){.} |
| \end{pspicture} |
\end{pspicture} |
| \end{center} |
\end{center} |
|
|
| we accept $AB$ as a unit, then $BC$ is two units long, $CD$ is a fifth of a unit, $DE$ is four fifths of a unit, $AC$ is three units, etc. |
we accept $AB$ as a unit, then $BC$ is two units long, $CD$ is a fifth of a unit, $DE$ is four fifths of a unit, $AC$ is three units, etc. |
|
|
| In two-dimensional space, length usually goes along the $x$ axis while height goes along the $y$ axis. The same holds for three-dimensional space. For triangles, pentagons and higher $n$-gons it is customary to refer to the dimension of any side as its length. The length of a circle's side is called its circumference. |
In two-dimensional space, length usually goes along the $x$ axis while height goes along the $y$ axis. The same holds for three-dimensional space. For triangles, pentagons and higher $n$-gons it is customary to refer to the dimension of any side as its length. The length of a circle's side is called its circumference. |
|
|
| In set theory, length measures the number of elements a set (or one-dimensional array) has. For example, {2, 5, 11, 23, 47} has length 5. |
In set theory, length measures the number of elements a set (or one-dimensional array) has. For example, {2, 5, 11, 23, 47} has length 5. |
|
|
|
|
