The circumference of a circle passing through the point $(4,6)$ with two normals represented by $2 x-3 y+4=0$ and $x+y-3=0$ is

Consider the point $P(\alpha, \beta)$ on the line $2 x+y=1$. If the $P$ and $(3,2)$ are conjugate points with respect to the circle $x^2+y^2=4$, then $\alpha+\beta$ is equal to

If $(1,3)$ is the mid-point of a chord of the circle $x^2+y^2-4 x-8 y+16=0$, then the area of the triangle formed by that chord with the coordinate axes is