Equation for a circle I'm reading a book about Calculus on my own and am stuck at a problem, the problem is

There are two circles of radius $2$ that have centers on the line $x = 1$ and pass through the origin. Find their equations.

The equation for circle is $(x-h)^2 + (y-k)^2 = r^2$
Any hints will be really appreciated.
EDIT: Here is what I did. I drew a triangle from the origin and applied the pythogoras theorem to find the perpendicular, the hypotenuse being $2$ ($\text{radius} = 2$) and base $1$ (because $x = 1$), the value of y-coordinate is $\sqrt3$. Can anyone confirm if this is correct?

HINT: Find out what points $(x, y)$ with $x = 1$ also have distance $2$ to the origin. What would these points represent?
