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

In $\Delta ABC$,if $\angle A = \angle B + \angle C$,then $\angle A = \ldots$ (in $^{\circ}$)

In the following figure,ray $BA$ is perpendicular to line $CD$. If $x: y: z = 4: 5: 6$,then find the values of $x, y,$ and $z$.

$\angle A$ and $\angle B$ are supplementary angles. If $\angle A = 3x - 10^{\circ}$ and $\angle B = 2x + 30^{\circ}$,then find $\angle A$ and $\angle B$.

In the given figure,if $PQ \parallel RS$ and $RS \parallel TU$,and $y: z = 7: 8$,find $x$.

In the figure,$BA \parallel ED$ and $BC \parallel EF.$ Show that $\angle ABC + \angle DEF = 180^{\circ}.$