In the given figure lines $PQ$ and $RS$ intersect in point $O$. If $\angle POR+\angle QOT=70°$ and $\angle QOS=40°$, then find the measures of $\angle QOT$ and reflex $\angle ROT$.

In the adjoining figure, lines $AB$ and $LM$ intersect in a point $O$. If $\angle NOB=90°$ and $x:y=2:3$ then find the value of $z$.

In the given figure $\angle ECD=\angle EDC$ then prove that $\angle ECA=\angle EDB$.

In the given figure $a+b=c+d$ then prove that $LOM$ is a straight line.

In the given figure, $AOB$ is a straight line. Ray $OC$ is perpendicular to $AB$. There is another ray $OD$ between ray $OA$ and $OC$. Prove that $\angle COD=\frac{1}{2}\left(\angle BOD-\angle AOD\right)$

Complete the table by observing the given figure

Complete the table by observing the given figure