R. D. Sharma Solutions for Chapter: Circles, Exercise 1: EXERCISE 8.1

The common point of a _____ and the circle is called the point of tangency.

A circle may have _____ parallel tangents.

A tangent to a circle intersects it in _____ point(s). ( Write answer in words)

A line intersecting a circle in two points is called a _____.

The angle between the tangent at a point on a circle and the radius through the point is _____$°$. 

How many tangents can a circle have?

$\mathrm{O}$ is the center of a circle of radius $8 \mathrm{c}\mathrm{m}$. The tangent at a point $\mathrm{A}$ on the circle cuts a line through $\mathrm{O}$ at $\mathrm{B}$ such that $\mathrm{A}\mathrm{B}=15 \mathrm{c}\mathrm{m}.$ Find $\mathrm{OB}$.

If the tangent at a point $\mathrm{P}$ to a circle with centre $\mathrm{O}$ cuts a line through $\mathrm{O}$ at $\mathrm{Q}$ such that $\mathrm{PQ}=24 \mathrm{cm}$ and $\mathrm{OQ}=25 \mathrm{cm}$. Find the radius of the circle. (Write the numeral value as final answer i.e without unit.)