If a transversal intersects two parallel lines then the sum of interior angles on the same side of the transversal is _____.

The number of angles formed by a transversal of two lines is _____

In $△ABC, \angle A=76°,\angle B=48°$, $\therefore \angle C=$_____ 

Ray $PQ$ and ray $PR$ are perpendicular to each other. Points $B$ and $A$ are in the interior and exterior of $\angle QPR$ respectively. Ray $PB$ and ray $PA$ are perpendicular to each other.

Draw a figure showing all these rays and write a pair of complementary angles.

Prove that, if a line is perpendicular to one of the two parallel lines, then it is perpendicular to the other line.

In figure, measures of some angles are shown. Using the measures find the measures of $\angle x$ and $\angle y$. Hence show that line $l \parallel$ line $m$.

Line $AB \parallel CD \parallel EF$  and line $QP$ is their transversal. If $y:z=3:7$ then the measure of $\angle x$ is $k°$. Find the value of $k$.