Find the measure of the complementary angle of an angle of $44^{\circ}$. (in $^{\circ}$)

If two lines intersect each other,then the vertically opposite angles are.........

Prove that the sum of the three angles of a triangle is $180^{\circ}$.

An angle is $40^{\circ}$ less than its supplementary angle,then its measure is $\ldots \ldots \ldots .$ (in $^{\circ}$)

Find the measure of the complementary angle of the supplementary angle of an angle having measure $128^{\circ}$. (in $^{\circ}$)

Lines $AB$ and $CD$ intersect at $P$. If $\angle APC = 2x + 30^{\circ}$ and $\angle BPD = 4x - 20^{\circ}$,then find $x$,$\angle APC$,and $\angle BPD$.