Question

The radius of the circle passing through the point $(6,2)$ and two of whose diameters are $x+y=6$ and $x+2y=4$ is:

• A. $4$
• B. $6$
• C. $20$
• D. $\sqrt{20}$

Answer 1

The correct option is D $\sqrt{20}$

Point of intersection of the given diameters is $(8,-2)$ which is the centre of the circle

Also the circle pass through the point $(6,2)$, so the radius is $=\sqrt{(8-6{)}^2+(-2-2{)}^2}=\sqrt{20}$