Answer
equation in standard form: $(x-1)^2+(y-2)^2=4$
center: $(1, 2)$
radius = $2$
Work Step by Step
The general equation for a circle with radius $r$ and centre $(h,k)$ is $(x-h)^2+(y-k)^2=r^2$.
The distance between the center $(1, 2)$ and the point on the circle $(1,0)$, since they belong to the same vertical line, is equal to $2-0=2$ units.
Hence, the standard form of the circle's equation is:
$(x-1)^2+(y-2)^2=2^2\\
(x-1)^2+(y-2)^2=4$