An angle whose measure is $90^{\circ}$ is called a $\ldots \ldots \ldots$

$A$ straight angle has measure......... (in $^{\circ}$)

$A$ part of a line with one end point is called a $\ldots \ldots \ldots .$

$A$ part [or portion] of a line with two end points is called a $\ldots \ldots \ldots$

In the figure,ray $OS$ stands on a line $POQ$. Ray $OR$ and ray $OT$ are angle bisectors of $\angle POS$ and $\angle SOQ$,respectively. If $\angle POS = x$,find $\angle ROT$. (in $^o$)

In the figure,sides $QP$ and $RQ$ of $\Delta PQR$ are produced to points $S$ and $T$ respectively. If $\angle SPR = 135^o$ and $\angle PQT = 110^o$,find $\angle PRQ$. (in $^o$)