Mathematics - Circle Question with Solution | TestHub

The centres of two circles $C_1$ and $C_2$ each of unit radius are at a distance of 6 units from each other. Let ' $P$ ' be the midpoint of the line segment joining the centres of $C_1$ and $C_2$ and $C$ be a circle touching circles $C_1$ and $C_2$ externally. If a common tangents to $C_1$ and $C$ passing through ' $P$ ' is also a common tangent to $C_2$ and $C$. Then the radius of the circle $C$ is