Assertion (A)	Reason (R)
If two tangents are drawn to a circle from an external point then they subtend equal angles at the centre.	A parallelogram circumscribing a circle is a rhombus.

In the given figure, $O$ is the centre of a circle, $PQ$ is chord and the tangent $PT$ at $P$ makes an angle of $50°$ with $PQ$. Then find the value of $\angle POQ$.

 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.

In the given figure, $PA$ and $PB$ are two tangents from an external point $P$ to a circle with centre $O$. If $\angle PBA=65°$ and the sum of  $\angle OAB$ and $\angle APB$ is $k°$, then find the value of $k$.