In $\Delta PQR$,$\angle P = 42^{\circ}$ and $\angle Q = 75^{\circ}$,then find $\angle R$. (in $^{\circ}$)

In the given figure,if $PQ || RS$,$RS || MN$ and $y: z = 7: 11$,then find $x$. (in $^o$)

$\angle A$ and $\angle B$ are complementary angles. If $\angle A = \angle B - 20^{\circ}$,then find $\angle A$ and $\angle B$.

In $\Delta ABC$,the bisectors of $\angle B$ and $\angle C$ intersect each other at $I$. Prove that $\angle BIC = 90^{\circ} + \frac{1}{2} \angle A$.

An angle which is greater than $180^{\circ}$ but less than $360^{\circ}$ is called a $\ldots \ldots \ldots .$.

If one of the angles of a triangle is $130^{\circ},$ then the angle between the bisectors of the other two angles can be (in $^{\circ}$)