A line can be named with a script letter or using the names of two points on the line. Line [tex]\ell[/tex] has three points on it: F, B, W. Any of the 6 possible pairings of those points can be used to name the line. When the line is named using a pair of points, they must have a double-ended arrow over the top. Here are the 6 possible alternate names for line [tex]\ell[/tex].
[tex]\ \ \overleftrightarrow{BF} \text{, } \overleftrightarrow{BW} \text{, } \overleftrightarrow{FB} \text{, } \overleftrightarrow{FW} \text{, } \overleftrightarrow{WB} \text{, } \overleftrightarrow{WF}[/tex]
