From the image, I need to find radius r.
I have a circle(R) whose center is $(0,0)$ and has a radius $R$.
I need to find radius $r$ of circle(r) which is internal and tangent to the circle $R$.
Circle(r) is also tangent to a vertical line at a distance $a$ from the origin Circle(r)'s centre is on a horizontal line that is distance $b$ from the vertical
I'm not able to find the answer.