# Length of the Side of a Triangle

The distance from one endpoint to another endpoint of a side in a triangle is defined length of the side of a triangle.

A triangle is formed by three line segments which become sides of it. The lengths of the sides are exactly equal to the lengths of the respective line segments because the line segments are transformed as sides of the triangle.

Previously, the distance from one endpoint to another endpoint of a line segment is its length. Now, the distance from one interactive point of one endpoint to another interactive point of another endpoint of the line segment is length of that side. So, the distance from one vertex to another vertex in a triangle is length of the respective side.

## Example

Look at the triangle $XYZ$. The sides are $\stackrel{‾}{XY}$, $\stackrel{‾}{YZ}$ and $\stackrel{‾}{ZX}$ and their lengths are $XY$, $YZ$ and $ZX$ respectively.

• The length of the side $\stackrel{‾}{XY}$ is $XY$ and it is evaluated by measuring the distance either from the vertex $X$ to vertex $Y$ or distance from the vertex $Y$ to vertex $X$.
• The length of the side $\stackrel{‾}{YZ}$ is $YZ$ and it is evaluated by measuring the distance from vertex $Y$ to vertex $Z$ and vice-versa.
• In this same method, the length of the side $\stackrel{‾}{ZX}$ is $ZX$ and it is evaluated by measuring the distance from vertex $Z$ to vertex $X$ and it is equal to distance from vertex $X$ to vertex $Z$.