3. Multiple choice question III

1.

In the figure, $O$ is the centre of a circle and diameter $AB$ bisects the chord $CD$ at a point $E$ such that $CE = ED = 8 \ cm$ and $EB = 4 \ cm$. The radius of the circle is:

 

2. In the figure, $PQRS$ and $PTVS$ are two cyclic quadrilaterals. If $\angle QRS = 100^\circ$, then $\angle TVS =$