In how many points, does a line intersect the circle at most?

A line, which intersects the circle in two points, is called as _____.

A line, which intersects the circle exactly at one point, is called a _____.

The common point of tangent to a circle and the circle is called as _____. [Centre / Point of contact / Concurrent point]

If the distance between two parallel tangents of a circle of radius $8 \mathrm{cm}$ is $k \mathrm{cm}$ then find $k$.

If a number of circles pass through the endpoints $A$ and $B$ of a line segment $AB$, then their centres lie on the perpendicular bisector of $AB$. Prove it.

In two concentric circles, the chord of the larger circle which touches the smaller circle, is bisected at the point of contact. Prove it.

If angle between two tangents drawn from a point $P$ to a circle of radius $a$ and centre $O$ is $90°$, then $OP=\sqrt{2}a$.

Prove that the tangent to the circumcircle of an isosceles triangle $ABC$ at $A$, in which $AB=AC,$ is parallel to $BC$.