91Ó°ÊÓ

The theorem 3-6 can be used which states that the relation between two lines is parallel only when a separate line travels through these two lines and the angles which are positioned on the same side are supplementary which means that their measurement will be equal to if they are added.

The provided figure consists of only two angles $∠LAS$and $∠AST$where $∠LAS$consists of two angles which are $∠LAT$and $∠TAS$along with this $∠LAS$and $∠AST$are positioned on the same side and are supplementary because:

$m∠LAS+m∠AST=\left(m∠LAT+m∠TAS\right)+m∠AST$

role="math" localid="1637822945923" $=\left(46+44\right)+90$

role="math" localid="1637822952381" $=180$

Using the theorem 3-6 determine the lines that are having a parallel relation between them.

$\stackrel{¯}{LA}||\stackrel{¯}{TS}$