If the angle between two radii of a circle is $130°$ then the angle between the tangents at the ends of the radii is

 If tangents $PA$ and $PB$ from a point $P$ to a circle with centre $O$ are drawn so that $\angle APS=80°$ then $\angle POA=$

In the given figure, $AD$ and $AE$ are the tangents to a circle with centre $O$ and $BC$ touches the circle at $F$. If $AE=5 \mathrm{cm}$, then perimeter of $∆ABC$ is

In the given figure, a quadrilateral $ABCD$ is drawn to circumscribe a circle such that its sides $AB, BC, CD$ and $AD$ touch the circle at $P, Q, R$ and $S$ respectively. If $AB=x \mathrm{cm}, BC=7 \mathrm{cm}, CR=3 \mathrm{cm}$ and $AS=5 \mathrm{cm}$ find the value of $x$.

In the given figure, $PA$ and $PB$ are the tangents to a circle with centre $O$. Show that the points $A, O, B, P$ are concyclic.

Two tangent segments $BC$ and $BD$ are drawn to a circle with centre $O$ such that $\angle CBD=120°$. Prove that $OB=2 BC$.

A circle can have _____ parallel tangents at the most.

The common point of a _____ to a circle and the circle is called the Point of Contact.