Question

Consider a circle $C$ which touches the $y-$axis at $(0,6)$ and cuts off an intercept $6\sqrt{5}$ on the $x-$axis. Then the radius of the circle $C$ is equal to

• A. $\sqrt{53}$
• B. $9$
• C. $8$
• D. $\sqrt{82}$

Answer 1

The correct option is B $9$



$r^2=6^2+(3\sqrt{5}{)}^2=81$
$\Rightarrow r=9$